Synthesis and Structure of Pyrazole-Containing Ferrocenyl Ligands for

The Development of Enantioselective Rhodium-Catalysed Hydroboration of Olefins. Anne-Marie Carroll , Timothy?P. O'Sullivan , Patrick?J. Guiry. Advance...
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Organometallics 1995, 14, 5415-5425

Synthesis and Structure of Pyrazole-Containing Ferrocenyl Ligands for Asymmetric Catalysis Urs Burckhardt, Lukas Hintermann, Anita Schnyder, and Antonio Togni* Laboratory of Inorganic Chemistry, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092 Zurich, Switzerland Received June 20, 1995@

A series of new chiral ferrocenyl chelating ligands containing a tertiary phosphine and a pyrazole moiety (3)have been obtained in moderate to good yields from the reaction of the corresponding phosphinoferrocenyl amine derivatives la-k with the V-I-pyrazoles 2a-w in acetic acid at temperatures between 70 and 90 "C. For unsymmetrically substituted pyrazoles a remarkable site selectivity is observed, leading in most cases to only one regioisomer. Six compounds have been characterized by X-ray diffraction and were found to display very similar conformational features. Scheme 1

Introduction Progress in asymmetric catalysis relies on the design of new chiral ligands, an important aspect in this regard being the synthetic versatility of the system chosen. We have been interested in chelating ferrocenyl ligands,l because they offer the unique opportunity of varying the nature of the two ligating moieties attached to the same cp ring independently from one anothern2As shown in Scheme 1, the assembly of these ligands requires two consecutive synthetic steps, the first utilizing an electrophilic and the second a nucleophilic ligand synthon. In recent years important developments in asymmetric catalysis have been achieved by using nitrogencontaining ligand^.^ In particular, the combination of nitrogen and phosphorus donor atoms has led to highly selective palladium catalysts for allylic substitution reaction^.^ Moreover, the coordination chemistry of the pyrazolyl fragment, most often as imbedded in a tris(pyrazolyl)hydroborate, has been thoroughly investigated over the past two decade^.^ However, reports on the incorporation of this heterocycle into chiral ligands Abstract published in Advance ACS Abstracts, October 1, 1995. (1)For reviews, see: (a) Hayashi, T. In Perrocenes: Homogeneous Catalysis, Organic Synthesis, Materials Science; Togni, A., Hayashi, T., Eds.; VCH: Weinheim, Germany, 1995;pp 105-142. (b) Sawamura, M.; Ito, Y. Chem. Rev. 1992,92,857-871. See also: ( c ) Hayashi, T.; @

Mise, T.; Fukushima, M.; Kagotani, M.; Nagashima, N.; Hamada, Y.; Matsumoto, A.; Kawakami, S.; Konishi, M.; Yamamoto, K.; Kumada, M. Bull. Chem. SOC.Jpn. 1980,53,1138-1151. (2)(a) Togni, A.; Breutel, C.; Schnyder, A.; Spindler, F.; Landert, H.; Tijani, A. J. Am. Chem. SOC.1994,116,4062-4066. (b) Breutel, C.; Pregosin, P. S.; Salzmann, R.; Togni, A. J. Am. Chem. SOC.1994, 116,4067-4068. (c) Togni, A.; Breutel, C.; Soares, M. C.; Zanetti, N.; Gerfin, T.; Gramlich, V.; Spindler, F.; Rihs, G. Inorg. Chim. Acta 1994, 222,213-224. (d)Abbenhuis, H. C. L.; Burckhardt, U.; Gramlich, V.; Togni, A.; Albinati, A,; Muller, B. Organometallics 1994,13,44814493.(e)Abbenhuis, H. C. L.; Burckhardt, U.;Gramlich, V.; Kollner, C.; Pregosin, P. S.; Salzmann, R.; Togni, A. Organometallics 1996,14, 759-766. (0 Schnyder, A,; Hintermann, L.; Togni, A. Angew. Chem. 1995,107,996-998;Angew. Chem., Int. Ed. Engl. 1995,34,931-933. (3) For a recent review, see: Togni, A.; Venanzi, L. M. Angew. Chem. 1994,106,517-547; Angew. Chem., Int. Ed. Engl. 1994,33,497-526. (4)For successful chiral P,N-ligands recently reported, see: (a) von Angew. Chem., Matt, P.; Pfaltz, A. Angew. Chem. 1993,105,614-615; Int. Ed. Engl. 1993,32,566-567.(b)von Matt, P.; Loiseleur, 0.;Koch, G . ; Pfaltz, A,; Lefeber, C.; Feucht, T.; Helmchen, G. Tetrahedron: Asymmetry 1994,5,573-584.(c) Sprinz, J.;Helmchen, G. Tetrahedron Lett. 1993,34, 1769-1772. (d) Sprinz, J.;Kiefer, M.; Helmchen, G.; Zsolnai, L. Tetrahedron Lett. Reggelin, M.; Huttner, G.; Walter, 0.; 1994,35,1523-1526. (5)See, e.g.: (a) Trofimenko, S. Chem. Reu. 1993,93,943-980.(b) Trofimenko, S.Prog. Inorg. Chem. 1986,34,115-210.

Q276-7333l95/2314-5415$Q9.QQlQ

Electrophilic synthon

Nucleophilic synthon

information)

as well as applications to homogeneous catalysis are still quite rare.6 This is somewhat surprising, since this kind of derivative is synthetically easily accessible, and the substitution pattern of the five-membered ring can be varied virtually with no restrictions. We recently reported the successful application of some novel pyrazole-containing ferrocenylphosphines in the asymmetric rhodium-catalyzed hydroboration of styrene with catecholborane.2f Our new ligands have been shown to afford the highest known enantioselectivities for this particular reaction. Furthermore, they were found to exhibit a pronounced electronic effect on stereoselectivity, depending on the nature of the pyrazole substituents. In this paper we present full experimental details for the preparation, characterization, and structure of this new class of ligands.

Results and Discussion Synthesis. A series of pyrazole ligands has been obtained from the reaction of a dimethyl{1424phosphino)ferrocenyl]ethyl}amine (la-k) and the corresponding VI-pyrazole (aa-w), as illustrated in Scheme 2. This SN1-like substitution reaction is carried out in acetic acid at temperatures between 70 and 90 "Cover 3-7 h and occurs (via a ferrocenyl carbocationic intermediate) with retention of configuration at the stereo(6)(a) Bovens, M.; Togni, A,; Venanzi, L. M. J . Organomet. Chem. 1993,451,C28-C31. (b) Tokar, C. J.; Kettler, P. B.; Tolman, W. B. Organometallics 1992,11,2737-2739.( c ) LeCloux, D.D.; Tolman, W. B. J . Am. Chem. Soc. 1993,115,1153-1154.(d) LeCloux, D.D.; Tokar, C. J.; Osawa, M.; Houser, R. P.; Keyes, M. C.; Tolman, W. B. Organometallics 1994,13,2855-2866. (e) Christenson, D.L.; Tokar, C. J.; Tolman, W. B. Organometallics 1996,14,2148-2150.

0 1995 American Chemical Society

5416 Organometallics, Vol. 14, No. 11, 1995

Burckhardt et al.

Scheme 2 0 '

R

Scheme 3

0 w

R

3

3aa-ke

NMe, la-k

genic center.I As compared to the corresponding reaction with a secondary phosphine as a nucleophile,2athe transformation involving pyrazoles was found to be more sluggish. Besides the desired compounds, varying amounts of unidentified decomposition products were formed. Nevertheless, the ligands were isolated in pure form after chromatographic purification andor recrystallization, generally in moderate yields (up to 78%). Table 1collects all the derivatives prepared, along with some selected analytical data. Several pyrazoles have been reported previously in the literature; some others are new. Since their preparation was achieved via conventional synthetic methods,8 they will not be described in detail here, and only the triptycyl derivative 2d is given as a representative (Sd)with N,Nexample. Reaction of 1-a~etyltriptycene~ dimethylformamide diethylacetal according to a reported procedurelo afforded 3-(dimethylamino)-l-(9triptycy1)S-propen-1-one (6d)in 65%yield. The latter was converted to the desired LH-pyrazole 2d by treatment with hydrazine, as illustrated in Scheme 3. In the case of a nonsymmetrical pyrazole 3,5-substitution pattern, a potential regioselectivity problem arises for the reaction with the ferrocene derivatives 1, because the two pyrazole nitrogen atoms are not equivalent. However, besides the two cases described below, only one regioisomer was generally detected and isolated. The common observation is that the nitrogen adjacent to the less bulky andor less electron-withdrawing group will behave as the nucleophilic center (becomes alkylated). Considering that the pyrazolyl fragment ends up at a sterically demanding secondary center, it is not surprising that the simple argument based on the different bulks of the substituents correctly predicts the regioselectivity. However, for sterically similar 3,5-substituents it is known that N-alkylation tends to give mixtures of the two regioisomers, the ratio of which is often dependent on the reaction conditions.ll (7) (a)Marquarding, D.; Klusacek, H.; Gokel, G.; Hoffmann, P.; Ugi,

I. J . Am. Chem. SOC.1970, 92, 5389-5393. (b) Gokel, G. W.; Marquarding, D.; Ugi,I. K.J.Org. Chem. 1972,94,3052-3058. (c) Gokel, G. W.; Ugi, I. K. J. Chem. Educ. 1972,49, 294-296. (8) (a) Kirschke, K. In Methoden der Organischen Chemie (HoubenWeyl); Thieme: Stuttgart, Germany, 1994; Hetarene IIb"eil2 Vol. E8b, pp 399-763. (b) Fusco, R. In Pyrazoles, Pyrazolines, Pyruzolidines, Indazoles, and Condensed Rings; Wiley, R. H., Ed.; Interscience: New

York, 1967; pp 1-176. (9)9-Acetyltriptycene was prepared from the commercially available 9-acetylanthracene by cycloaddition of benzyne, as reported for 9-bromotriptycene. See: (a) Jefford, C. W.; McCreadie, R.; Muller, P.; Siegfried, B. J . Chem. Educ. 1971,48, 708-710. (b) Molle, G.; Bauer, P.; Dubois, J. E. J. Org. Chem. 1983, 48, 2975-2981. (10)Brunner, H.; Scheck, T. Chem. Ber. 1992, 125, 701-709. (11)Katritzky, A. R.; Lagowsky, J. M. In Comprehensive Heterocyclic Chemistry; Potts, K. T., Ed.; Pergamon: Oxford, U.K., 1984; pp 39110.

2d

6d

In such cases the position of the incoming alkyl substituent may or may not be related to the stabilization of one of the two possible tautomeric forms. It has been shown that a correlation exists between the sign of the , of the substituent and its Hammett parameter a position in the major tautomer at equilibrium.12 Thus, electron-withdrawing groups (positive a,,,) prefer position 3, whereas electron-donating substituents (negative a,,,)are rather to be found a t position 5 . In the case of the 5-methyl-3-tduoromethyl derivative 3af this thermodynamic argument would predict the preferred formation of the regioisomer opposite to the one that was found (electrophilic attack a t the doubly bonded nitrogen). This is taken as an indication that for this particular pyrazole N-alkylation is kinetically controlled. The 3-isopropyl-5-methyl ligand 3ag was found to be accompanied by its regioisomer, whereby a ratio of 7:3 was determined by NMR of the crude mixture (the minor isomer could not be obtained in pure form). This is not too surprising, since both the electronic and steric differences between the two substituents are relatively small. Finally, the 9-anthryl derivative 3aq does not fit this simple steric argument. In analogy to all other aryl-substituted pyrazoles, one would in fact expect the formation of only one regioisomer. A 5:l mixture of the two possible products was found instead, the major isomer being the expected one (vide infra). A tentative explanation for the formation of the minor isomer is as follows. A charge-transfer (stacking) interaction between the 9-anthryl moiety and the ferrocenyl carbocationic intermediate could enable the approach of the nitrogen atom adjacent to the electrophilic center, as illustrated in Chart 1. Such an interaction would overcome part of the unfavorable steric repulsions resulting in the product. Structural Characteristics of the Ligands. In order to define the conformational properties of the ligands, and to prove the structure of the single regioisomers obtained from the reactions with unsymmetrically substituted pyrazoles, X-ray crystallographic studies of several compounds have been carried out. Suitable single crystals were obtained for the ligands 3af, 3ah, 3aj, 3aq', 388, and 3ec by recrystallization from hexane (3ah, 3 4 ) or from mixtures of CHzC12 and hexane (all others). Because of the structural similarities existing between the six compounds, only a representative view of one molecule is shown in Figure 1for the compound 3aq' (ORTEP views for all other com(121Elguer0, J.; Marzin, C.; Katritzky, A. R.; Linda, P. Adv. Heterocycl. Chem. 1976, Suppl. 1 (The Tautomerism of Heterocycles).

Organometallics,Vol. 14,No.11, 1995 5417

Pyrazole-ContainingFerrocenyl Ligands

Table 1. Selected Properties of Pyrazole-ContainingFerrocenyl Ligands R2

I

FeCp

1

2 3

4 5 6 7 8

9 10 11

12 13 14 15 16 17 18

19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 a

3ac 3ad 3ae 3af 3ag 3ah 3ai 34 3ak 3al 3am 3an 3ao 3ap 3aq 3aq' 3ar 3as 3at 3au 3av 3aw 3be 3ce 3de 3ec 3ee 3ej 3ew 3fe 3ge 3gi 3gw 3he 3ie 3je 3jj 3ke

2-9. 9-triptycyl Me CF3 iPr CY OEt Ph 2-9. 3-9. 4-9. 2,4(OMe)zPh l-naphthyl 2-naphthyl 9-anthryl Me ferrocenyl Me Me Me CF3 iPr Me Me Me 2-Py Me Ph CF3 Me Me Ph CF3 Me Me Me Ph Me

H

H H Me Me Me Me Me Me Me Me Me Me Me Me H Me H 9-An H Me Me Me NO2 Me Br Me H CF3 H iPr H Me H Me Me H H H Me H H Me H CF3 H Me H Me H Me H CF3 H Me H Me H Me H Me H Me

H H H H H H H H H H H H H

Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph Ph 4-F-Ph 4-Cl-Ph 4-Me-Ph 4-CF3-Ph 4-CF3-Ph 4-CF3-Ph 4-CFs-Ph 4-NMez-Ph 4-OMe-Ph 4-OMe-Ph 4-OMe-Ph 3,5-Mez-Ph 3,5-(CF3)2-Ph Bu Bu CY

64 41 78 74 55 35 26 26 24 55 64 32 37 19 45 28 37 7 18 40 63 62 35 43 67 59 25 60 67 59 51 50 57 20 28 53 63 26 14 45

363 303 291 -200 329 282 256 297 293 338 330 294 365 314 386 337 338 265 -283 310 296 284 154 265 -308 -354 -323 -323 -263 -292 -214 -366 -324 -333 -200 -289 -251 -249 -225 -128

131 122 121 167 127 148 oil 94 116 171 130 167 158 83 192 129 202 217 163 a

163 150 125 130 136 150 156

201 112 102 73 177 167 112 93 182 122 oil oil 100

-24.0 -25.3 -25.2 -26.0 -24.1 -24.7 -23.9 -23.8 -23.6 -23.9 -24.1 -23.9 -24.5 -23.9 -23.9 -23.9 -24.2 -24.0 -23.8 -24.2 -26.1 -25.0 -25.5 -22.9 -26.6 -26.0 -24.9 -24.6 -24.0 -23.6 -25.3 -28.5 -27.6 -27.7 -29.1 -23.9 -63.3 -42.3 -42.3 -16.1

4.05 4.11 4.08 4.09 4.05 4.08 4.04 4.04 4.05 4.09 4.06 4.08 4.10 4.09 4.12 4.14 4.08 3.82 4.07 4.08 4.13 4.09 4.15 4.03 4.06 4.07 4.04 4.10 4.10 4.15 4.16 4.08 4.06 4.13 4.13 4.08 4.07 4.13 4.18 4.14

5.77 5.86 5.84 6.01 5.58 5.72 5.61 5.62 5.46 5.66 5.69 5.70 5.72 5.65 5.75 5.75 5.85 5.10 5.54 5.63 5.74 5.63 5.97 5.52 5.57 5.57 5.57 5.90 5.58 5.71 5.91 5.56 5.56 5.66 5.91 5.64 5.65 5.58 5.74 5.51

1.92 1.99 1.96 2.10 1.70 1.84 1.84 1.86 1.79 1.91 1.87 1.88 1.88

1.91 1.98 1.96 2.09 1.68 1.92 1.80 1.82 1.78 1.94 1.92 1.78 1.77 1.80 1.95 1.79 1.91 1.91 1.82 1.79 1.89 1.89 1.87 1.67 1.75 1.86 1.75

5.58 5.92 6.29 6.12 5.06 5.52 5.20 5.23 4.73 5.61 6.01 5.61 5.66 5.83 5.69 5.76 5.81 6.01 5.47

6.26 5.28 5.07 5.09 5.05 6.31 4.99 5.57 6.23 5.08 5.07 5.60 6.25 5.21 5.00 5.65 6.21 5.67

Not determined.

Chart 1

pounds are provided as Supporting Information). The bond distances and angles turn out to be rather routine and fall in the expected ranges.13 However, the six ligands examined show interesting common conforma(13)(a) Orpen, A. G.; Brammer, L.; Allen, F. H.; Kennard, 0.; Watson, D. G.; Taylor, R. J. Chem. Soc., Dalton Trans. 1989, Supplement 51-583. (b)Allen, F. H.; Kennard, 0.;Watson, D. G.;Brammer, L.; Orpen, A. G.; Taylor, R. J. Chem. SOC.,Perkin Trans. 2 1987, Supplement 51-519.

tional aspects. A selection of important torsion angles is given in Table 2, and Figure 2 illustrates the conformational similarities between the six different compounds. Thus, one recognizes the following common features. (1)The pyrazolyl ring and one of the two phosphinophenyl groups lie in a pseudoaxial position, pointing away from the ferrocene core (exo-axial). The corresponding diagnostic torsion angles C(l)-C(2)-C(6)N(1)and C(2)-C(l)-P(l)-Ci,,,(Ph,) are in the ranges 63-84" and 90- 104",respectively. The second phenyl ring is therefore in an endo-equatorial position with the angle C(5)-C( 1)-P( l)-Cipo(Phq) lying between 10 and 27". (2) In all but one derivative the planes defined by the pyrazolyl and the axial phenyl groups are nearly parallel, the angle between them varying from 12.1" (3a.j)to 23.5"(3af). The proximity of these two rings is possibly responsible for this relative arrangement, thereby mini-

Burckhardt et al.

5418 Organometallics, Vol. 14, No. 11, 1995

m C \

I3

~

C14'1

Figure 1. ORTEP view of one of the crystallographically independent molecules of the ligand 3aq' (30%probability ellipsoids). Table 2. Selected Torsion Angles (deg)"for 3af, 3ah, 3aj,3aq', 388, and 3ec torsion angle 3af 3ah 3 4 3aq'b 3as 3ec 71 63 80 80 76 84 C(l)-C(2)-C(6)-N(lY C(2)-C(1)-P(1)-C(Phm) 93 93 91 104 90 103

C(5)-C(l)-P(l)-C(Ph,,)

14 27 17 10 17 22 21 30 19 11 22 26 C(3)-C(2)-C(6)-C(7) 60 45 51 57 56 36 C(2)-C(6)-N(l)-N(2) 70 82 74 69 70 88 C(7)-C(6)-N(l)-N(2) 3 27 1 8 C(l)-P(l)-Ci~~o(Ph~~)- 1 1 C o r dPhiax) a Absolute values are given. The figures given correspond to average values for the three independent molecules in the unit cell. The numbering of relevant atoms for all compounds corresponds to that shown in Figure 1.

orientation of the axial phenyl ring, as reflected by the of 27', torsion angle C(l)-P(l)-C~~,o(Ph)-~o~~o(Ph) describing the rotation around the P-Ph axis, as compared to angles of 1-8" for all other compounds. (3) The nearly parallel arrangement of the axial phenyl and pyrazolyl rings may be considered as one of two possible low-energy relative conformations. For all ligands under study the observed one is such that the nitrogen atom N(2) is in an anti position with respect to the hydrogen atom attached to the stereogenic center C(6). This orientation is not expected to be well-suited for the ligands to coordinate in a chelating manner to a metal center, since the lone pairs of N(2) and of the phosphorus atom are pointing in roughly opposite directions. Therefore, in the coordinated form the pyrazolyl fragment is expected to be rotated by ca. 180" around the C(6)-N(l) axis, with respect to the free ligands. Such an arrangement would correspond to the second low-energy conformation having parallel pyrazolyl and phenyl rings.

Conclusions We have shown that a new class of chiral chelating ferrocenyl ligands incorporating a phosphine and a pyrazole is easily obtained by the unique substitution reaction occuring at the pseudo-benzylic stereogenic center of the ferrocenyl precursors 1. This simple synthetic approach allows the preparation of a great variety of ligands, the electronic and steric properties of which can easily be modified. This still uncommon aspect offers the opportunity to tailor the ligands to a specific reaction andlor substrate. We have already demonstrated the effectiveness of our new P,N chelating ligands in the Rh-catalyzed hydroboration of styrenes.2f On the basis of these first very encouraging results, we are currently exploring further asymmetric transition-metal-catalyzed reactions. We will be reporting on developments in this area in due course. Experimental Section

Figure 2. Superposition of the structures of the ligands 3af, 3ah, 3aj, 3aq', 388, and 3ec. The most significant

deviation from the common conformation is shown by the 9-anthryl derivative 3aq'. All ligands are shown in their @)-(I?) absolute configuration. mizing steric interactions between the two groups. A significant deviation from the described geometry is found in the 9-anthryl derivative 3aq' (minor isomer), where the latter interplanar angle (average value for the three independent molecules in the unit cell) is 69.4'. This is most likely due to the bulky 9-anthryl group, lying in an almost orthogonal orientation with respect to the pyrazolyl ring (the average interplanar angle being 81'1, thus "reaching over" to the phosphino fragment. The consequence of this is a different relative

General Considerations. All reactions with air- or moisture-sensitive materials were carried out under Ar using standard Schlenk techniques. Freshly distilled, dry, and oxygen-free solvents were used throughout. Routine 'H (250.133 MHz), 13C (62.90 MHz), 19F(188.31 MHz), and 31P NMR (101.26MHz) spectra were recorded with a Bruker AM 250 spectrometer. Chemical shifts are given in ppm, and coupling constants (4 are given in Hz. Merck silica gel 60 (230-400 mesh) was used for column chromatography. Optical rotations were measured with a Perkin-Elmer 341 polarimeter using 10 cm cells. The IR spectra were recorded on a Perkin-Elmer Paragon 1000 FT-IR spectrophotometer. Melting points were obtained from samples in open capillarytubes with a Buchi SMP-PO apparatus and are uncorrected. Elemental analyses and EI/MS spectra were performed by the "Mikroelementar-analytischesLaboratorium der ETH. Dimethyl[(R)-l-ferrocenylethyllamine, dimethyl[(S)-l-ferrocenylethyllamine, and dimethyl{(R)-l-[(S)-2-(bis(3,5-bis(trifluoromethyl)phenyl)phosphino)ferrocenyl]ethyl}amine (li)were obtained from Ciba Geigy AG. 1H-%azole (2a), 3,5-dimethyl(21.11 1H-pyrazole(2e),and 4-brom0-3,5-dimethyl-W-pyrazole

were used as received from Fluka AG. Dimethyl{(S)-l-[(R)2-(diphenylphosphino)ferrocenyl]ethyl}amine1c(la),dimethyl{(R)-l-~~S~-2-~diphenylphosphino)ferrocenyllethyl~a~ne1c (la'), dimethyl~(R)-l-[(S)-2-(bis(4-fluorophenyl)phosp~o)ferrocenyll(14) Unruh, J. D.; Christenson, R. J.Mol. Catal. 1982, 14, 19-34.

Pyrazole-Containing Ferrocenyl Ligands

Organometallics, VoE. 14,NO.11, 1995 5419

sec-butyllithium in hexane (17 mmol, 1.2 equiv), and 3.5 mL of bis(4-methylpheny1)chlorophosphine(17 mmol, 1.2 equiv), l-[(S)-2-(bis(4-methoxyphenyl)phosphino)ferrocenyllethyl}- according t o the general method. FC (silica, hexane/ethyl ~ -305 (c = 0.40, amine14 (lg),dimethyl{ (R)-l-[(S)-2-(bis(3,5-dimethylphenyl)- acetate 10A): yield 1.79 g (27%). [ a I z 3 = CHC13). lH NMR (CDCl3): 6 7.5-6.96 (m, 8 a r H), 4.36 (m, cp phosphino)ferr~cenyl]ethyl}amine~~ (lh), 3-phenyl-1H-pyraH), 4.23 (m, cp H), 4.15 (dq, J = 2.6, J = 6.9, CHMeN), 3.92 zoiel5(2b),3-(2-pyridyl)-lH-pyra~ole~~ (2c),3-(trifluoromethyl)(2n, 3-isopropy1-5-methyl-ZH-pyra~ole~~ (s, 5 cp H), 3.88 (m, cp H), 2.36 (s, PhMe), 2.27 (5, PhMe), 1.79 5-methyl-lH-pyra~ole~~ ( s , 2 NMe), 1.28 (d, J = 6.9, CHMeN). l3C{'H) NMR (CDC13): (2g), 3-cyclohexyl-5-methyl-lH-pyrazole15 (2h), 5-ethoxy-3methyl-1H-pyrazole17 (29, 3-phenyl-5-methyl-lH-pyra~ole~~ 6 138-128 (8 ar CH), 96.8 (C), 71.8 (cp CHI, 69.7 (5 cp CHI, 69.2 (cp CH), 68.2 (cp CH), 51.1 (CHMeN), 39.3 (2 NMe), 21.3 3-(2-pyridy1)-5-methyl-lH-pyra~ole~~ (2k), 3-(3-pyridyl)(21), 3-(4-pyridyl)-5-methyl-lH-pyra- (2 PhMe), 10.1 (CHMeN). 31P{1H}NMR (CDC13): 6 -25.3 (s). 5-methyl-VI-pyra~ole~~ zolel5 (2m), 3-(2,4-dimetho~yphenyl)-5-methyl-lH-pyrazole~~Anal. Calcd for C28H33FeNP: C, 71.65; H, 6.87; N, 2.98. Found: C, 71.64; H, 6.85; N, 2.68. (2n), 3-(a-naphthyl)-5-methyl-lH-pyra~ole'~ (20), 3-(P-naphDimethyl{(R)-l-[(S)-2-(bis(4-(dimethylamino)phenyl)thyl)-5-methyl-lH-pyra~ole'~ (2p),3-(9-anthryl)-5-methyl-Wphosphino)ferrocenyl]ethyl}amine (If): from 2 mL of pyrazole15(2q), 3-ferro~eny1-5-methyl-lH-pyrazole~~ (2r),3,4,5trimethyl-lH-pyrazole16(2s),3,5-dimethy1-4-nitro-lH-pyra~ole~~dimet hyl[(R) - 1-ferrocenylethyllamine (9.3 mmol, 1equiv) , 8.2 mL of 1.4 M sec-butyllithium in cyclohexane (11.3 mmol, 1.2 (2t),3,5-bis(trifluoromethyl)-1H-pyrazole'g(2v),3,bdiisoproequiv), and 6.77 g of bis(4-(dimethylamino)phenyl)chloro(2w),and dicyclohexylchlorophosphinezowere pyl-lH-pyra~ole'~ phosphine (22 mmol, 2.4 equiv), according to the general prepared by literature methods. method. FC (silica, hexane/ethyl acetate 5/1): yield 1.32 g General Method for the Synthesis of Chlorophos(27%). Mp: 182 "C dec. [ a I z 3= ~ -383 (c = 0.345, CHC13). 'H phines. The Grignard mixture (prepared in situ from 2.2 NMR (CDC13): 6 7.51-6.55 (m, 8 ar H), 4.33 (m, cp H), 4.22 equiv of magnesium and 2.2 equiv of alkyl or aryl bromide) (m,cpH),4.07(dq,J=2.6,J=6.9,CHMeN),4.06(m,cpH), was slowly added to a cooled solution of 1equiv of PClZ(NEt2) 3.94 (s, 5 cp H), 2.97 (s, 2 NMe), 2.89 (s, 2 NMe), 1.83 (s, 2 in ether. The precipitate was filtered off, and 2.2 equiv of dry NMe), 1.34 (d, J = 6.9, CHMeN). l3C{'H) NMR (CDCl3): 6 pyridine hydrochloride was added to the clear solution. The 136-112 (8 a r CHI, 71.6 (cp CHI, 69.5 (5 cp CH), 68.8 (cp CHI, mixture was stirred overnight and filtered, the solvent re67.9 (cp CH), 57.0 (CHMeN), 40.4 (2 NMe), 40.3 (2 NMe), 39.7 moved, and the oily residue distilled in vacuo. Yield: 12(2 NMe), 11.8 (CHMeN). 31PNMR (CDC13): 6 -28.4 (s). Anal. 80%. Calcd for C30H38FeN3P: C, 68.31; H, 7.26; N, 7.97. Found: C, General Method for the Synthesis of R*PFA (1). sec68.49; H, 7.41; N, 7.86. Butyllithium in cyclohexane (1.2 equiv) was added to a solution of dimethyl[@)-1-ferrocenylethyllamine (1equiv) in ether over Dimethyl{(R)-l-[(S)-2-(dibutylphosphino)ferrocenylla period of 20 min. The resulting red-brown solution was ethyl}amine (lj): from 3 mL of dimethyl[(R)-1-ferrocenylstirred at room temperature overnight, and then diaryl- or ethyllamine (14 mmol, 1 equiv), 10.5 mL of 1.6 M n-butyllithium in hexane (17 mmol, 1.2 equiv) and 5 g of dibutylchlorodialkylchlorophosphine (1.5-4 equiv) in 10 mL of ether was added. After 5 h reflux aqueous sodium hydrogencarbonate phosphine (28 mmol, 2 equiv), according to the general method. was slowly added with cooling in a ice bath. The resulting FC (silica, hexane/ethyl acetate 5/1): yield 3.19 g (57%). [ a l Z 3 ~ organic layer and the ether extracts from the aqueous layer = -80 (c = 0.55, CHC13). lH NMR (CDC13): 6 4.23 (m, cp H), were combined, washed with water, dried over anhydrous 4.17-4.11 (m, cp H), 4.09 (dq, J = 2.6, J = 6.9, CHMeN), 4.03 sodium sulfate, and concentrated in vacuo to afford a red oil. (s, 5 cp H), 4.01-3.91 (m, cp H), 2.06 (s, 2 NMe), 1.22 (d, J = 6.9, CHMeN), 1.94-0.76 (m, 6 Bu CH:! and 2 Bu CH3). 13CPurification by chromatography on silica, followed by recrys{'H} NMR (CDC13): 6 96.7 (C), 69.4 (5 CP CH), 69.3 (CP CHI, tallization from hexane, gave pure 1 as orange crystals. Dimethyl{(R)-1-[(S)-2-(bis(4-chlorophenyl)phosphino)- 68.7 (cp CH), 67.2 (cp CH), 56.6 (CHMeN),39.2 (2 NMe), 29.624.3 (6 Bu CH2),14.0 (Bu CH3), 13.8 (Bu CH3), 8.1 (CHMeN). ferrocenyl]ethyl}amine (IC): from 2 mL of dimethyl[fR)31P{1H}NMR (CDC13): 6 -39.8 (5). Anal. Calcd for C:!:!H361-ferrocenylethyllamine(9.3 mmol, 1equiv), 8.2 mL of 1.4 M FeNP: C, 65.83; H, 9.04; N, 3.49. Found: C, 66.26; H, 9.50; sec-butyllithium in hexane (11.2 mmol, 1.2 equiv) and 6 g of N, 3.23. bis(4-chlorophenyl)chlorophosphine(21 mmol, 2.2 equiv), according to the general method. Flash chromatography (FC) Dimethyl{(R)-1-[(S)-2-(dicyclohexylphosphino)ferro(silica, hexane/ethyl acetate lO/l): yield 1.744 g (37%). [ a I z 3 ~ cenyl]ethyl}amine (lk): from 3.35 g of dimethyl[(R)-1= -328 (C = 0.495, CHC13). 'H NMR (CDC13): 6 7.55-7.10 ferrocenylethyllamine (13 mmol, 1 equiv), 9.8 mL of 1.6 M (m, 8 ar H), 4.39 (m, cp H), 4.26 (m, cp H), 4.20 (dq, J = 2.5, n-butyllithium in hexane (15.7 mmol, 1.2 equiv), and 3.8 g of J = 6.9, CHMeN), 3.99 (s, 5 cp H), 3.80 (m, cp H), 1.80 (s, 2 dicyclohexylchlorophosphine (16.3 mmol, 1.25 equiv), according NMe), 1.25 (d, J = 6.9, CHMeN). 13C{'H} NMR (CDC13): 6 t o the general method. FC (silica, hexane/ethyl acetate 5/1): 136-127 (8 a r CH), 71.4 (2 cp CHI, 69.6 (5 cp CH), 68.3 (cp ~ -30 (c = 0.39, CHC13). 'H NMR yield 3.80 g (64%). [ a I z 3= CH), 57.1 (CHMeN), 38.7 (2 NMe), 8.2 (CHMeN). 31P{1H} (CDC13):6 4.26 (m, cp H), 4.23 (m, cp H), 4.08 (m, cp H), 4.05 NMR (CDC13): 6 -25.0 (s). Anal. Calcd for cz6H:!&l:!FeNP: (s, 5 cp H), 4.00 (dq, J = 2.7, J = 6.8, CHMeN), 2.10 (s, 2 NMe), C, 61.21; H, 5.14; N, 2.75. Found: C, 61.36; H, 5.36; N, 2.65. 1.27 (d, J = 6.8, CHMeN), 2.04-1.0 (m, 10 Cy CH:! and 2 Cy Dimethyl{(R)-l-[(S)-2-(bis(4-methylphenyl)phosphino)- CH). 13C{'H} NMR (CDC13): 6 69.7 (CP CH), 69.5 (5 CP CH), 68.2 (cp CH), 66.9 (cp CH), 56.2 (CHMeN), 39.0 (2 NMe), 36.3ferrocenyl1ethyl)amine (Id): from 3 mL of dimethyl[@?)26.2 (10 Cy CH2 and 2 Cy CH), 8.3 (CHMeN). 31P{1H}NMR 1-ferrocenylethyllamine(14 mmol, 1equiv), 10.5 mL of 1.4 M (CDC13): 6 -11.7 (s). Anal. Calcd for C:!6H&'eNP: C, 68.87; H, 8.89; N, 3.09. Found: C, 68.96; H, 8.91; N, 3.09. (15)General protocol for the preparation of 1H-pyrazoles (2):the corresponding 1,3-diketone (or the enamine analogon) was dissolved 9-Acetyltriptycene (Sd): synthesis analogous to that of or suspended in ethanol (ca. 10%). From a syringe 2 equiv of hydrazine 9-bromotri~tycene.~ From 20 g (0.09 mol) of 9-acetylanhydrate was added at room temperature. The mixture was stirred for thracene (4d) and benzyne, generated in situ with 30 g (0.22 10 min and then heated at reflux temperature for 30 min, unless otherwise stated. After complete removal of the solvent, the crude mol) of anthranilic acid and 32 g (0.28 mol) of isopentyl nitrite product was dissolved in dichloromethane, washed twice with water (in two portions), the crude product was recrystallized two to remove any unreacted hydrazine, dried, and purified as appropriate8 times from hot methanol t o give 11.8 g (44%) of 5d as an (16)Nishiwaki, T. J. Chem. SOC.B 1967,885-888. orange-brown powder, which was used without further puri(17)Wolff, W.Chem. Ber. 1904, 2827-2836. fication for the synthesis of 6d. Recrystallization from ethyl (18)Morgan, G. T.;Ackerman, I. J. Chem. SOC.1923, 1308-1318. (19) Claire, P. P.K.; Coe, P. L.; Jones, C. J.; McCleverty, J. A. J. acetateheptane of an analytical sample of 5d afforded brownFluorine Chem. 1991,51,283-289. ish yellow needles. Mp: 188 "C. 'H NMR (CDC13): 6 7.74 (m, (20)Voskuil, W.; Arens, J. F. Red. Trau. Chim. Pays-Bas 1963,82, 3 trp H), 7.43 (m, 3 trp HI, 7.07 (m, 6 trp H), 5.39 (s, 1H, trp 302-304.

ethyl}amine14(lb),dimethyl{(R)-l-[(S)-2-(bis(4(trifluoromethyl)phenyl)phosphino)ferr~cenyl]ethyl}amine~~ (le),dimethyl{(R)-

(ai,,

5420 Organometallics, Vol. 14,No. 11, 1995 H), 2.82(s, COMe). 13C{1H}NMR (CDC13): 6 206.7(COMe), 146.1,142.8(trp C), 125.3,124.8,123.5,123.4(trp CH), 54.4 (trp CH), 32.7(COMe). IR (cm-'1: 3067,3016,2962,1713 (C=O), 1459,1358,1236,1150,750,610,582. Anal. Calcd for Cz2H160: C, 89.16;H, 5.44.Found: C, 89.03; H, 5.58. 3-(Dimethylamino)-l-(9-triptycyl)-2-propen-l-one (6d): from 3 g (0.01mol) of 9-acetyltriptycene (5d)and cu. 5 mL (0.03mol) of NJ-dimethylformamide diethylacetal, analogously to the preparation of 3-(dimethylamino)-l-(2-pyridyl)2-pr0pen-l-one.'~The crude product was washed thoroughly with cold ethanol to yield 2.3g (65%)of 6d as a fine creamwhite solid. An analytical sample was recrystallized from hot acetone (white microcrystals). Mp: 297 "C. 'H NMR (CDC13): 6 8.05 (m, 3 trp H), 7.40(m, 3 trp H), 7.06-6.96(m, 6 trp H COCH), 5.35(s, trp H), 3.21,2.77 and CHN), 5.50 (d, J = 12.5, (br s, 2 NMe, cisltruns). 13C{1H}NMR (CDC13): 6 194.1(CO), 151.8(CHN), 146.8,145.2(trp C, 125.7,125.1,124.8,123.4 (trp CH), 100.4(COCH), 55.1(trp CHI, 33.2(NMe). IR (cm-I): 3056,2915(CH), 1712,1655,1563 (C=O, C-C), 1433,1350, 1278,1097,1073,891,758,640,624.Anal. Calcd for C25H21NO: C, 85.44; H, 6.02; N, 3.99.Found: C, 85.73; H, 5.93; N,

3.87.

Burckhardt et al.

6 150.5,138.8-125.8(ar CH, ar C), 101.9(pz CH), 93.6(cp C), 76.4(cp C), 72.0(cp CHI, 70.0(5 cp CH), 69.9(cp CHI, 69.8(cp CH), 56.2(CHMeN), 21.6(CHMeN). 31P{1H}NMR (CDCl3): 6 -25.3(s). IR (cm-I): 1497,1459,1433,1246,1043, 1001,816,742,694. MS ( m / z ) :540 (M+, loo%), 475 (M+ cp), 396 (M+ - Hpz), 355,331 (396- cp), 276 (396- Fe-cp), 253,183,144(Hpz+). Anal. Calcd for C33H29FeNzP: C, 73.34; H, 5.41;N, 5.18.Found: C, 73.14; H, 5.29;N, 5.00. 1-{(S)-1-[ (R)-2-(Diphenylphosphino)ferrocenyllethyl}3-(2-pyridyl)-lH-pyrazole(3ac): from la (300 mg, 0.68 "01) and 3-(2-pyridine)-VI-pyrazole (2c)(109mg, 0.75mmol, 1.1equiv), according to the general method. FC (silica, hexane/ ethyl acetate 2/1,2% NEt3): yield 288 mg (78%). Mp: 121 "C. [ a I z 3=~ +291 (c = 0.46,CHC13). lH NMR (CDC13): 6 8.52 (m, py CH), 7.71(m, 1 a r H), 7.62-7.50(m, 3 ar H), 7.35(m, 3 a r H), 7.09(m, 1 a r H), 7.03(m, pz CHI, 6.88-6.73(m, 5 ar H), 6.29(m, pz CH), 5.84(dq, J = 7.0, J = 3.3,CHMeN), 4.74 (m, cp H), 4.40(m, cp H), 4.08(s, 5 cp H), 3.86(m,cp H), 1.96 (d, J = 7.0, CHMeN). 13C{'H} NMR (CDC13): 6 150.1(py C), 148.6(py CH), 138.4,137.2, 135.7-127.1(ar CH, a r C, 121.3, 119.8(py CHI, 103.3(pz CH), 71.7(cp CHI, 69.6(5 cp CH), 69.3(cp CH), 69.0(cp CHI, 56.1(CHMeN), 21.1(CHMeN). 31P{'H} NMR (CDC13): 6 -25.2(8). IR (cm-I): 1592,1566,1490,

3-(9-Triptycyl)-lH-pyrazole (2d):from 2.0g (5.7mmol) 1458,1434,1405,1245,1217,1106,815,768,744,700,503, of 3-(dimethylamino)-l-(9-triptycyl)-2-propen-l-one (5d),ac484,469.MS ( m/ z ) : 541 (M+),476 (M+ - cp, loo%), 396 (M+ cording to the general method (12 h reflux time).I5 Recrys- Hpz), 331 (396- cp), 291,265,200,145 (Hpz+). Anal. Calcd tallization from hot EtOH and then from ethyl acetateheptane for C32H2eN3PFe: C, 70.99; H, 5.21; N, 7.76. Found: C, 70.77; yielded 1.43g (78%)of 2d as white needles. Mp: 251 "C dec. H, 5.46; N, 7.63. 'H NMR (CDC13): 6 11.4(br s, NH), 7.58(m, 3 trp H), 7.51(d, 1-{(R)-1-[(S)-2-(Diphenylphosphino)ferrocenyllethyl}1 pz CH, J = 259,7.46(m, 3 trp H), 7.07-6.94(m, 6 trp H), 3-(9-triptycyl)-lH-pyrazole(3ad): from la' (574mg, 1.30 6.77(d, 1 pz CH, J = 2.2),5.49(s, 1 trp H). W{lH} NMR mmol) and 3-(9-triptycyl)-lH-pyrazole (2d) (500 mg, 1.56 145.7(trp C), 125.0-123.1(4trp CHI, 124.8 (CDC13): 6 146.0, mmol, 1.2equiv), according to the general method. FC (silica, (pz CH), 108.1(pz CH), 54.5(trp CH). IR (cm-'1: 3168(NH), hexane/diethyl ether 4/1):yield 687mg (74%). Mp: 167 C. 3054,2952(CH), 1531,1449,1353,1213,1062,914,749,634. [aI23~ = -200 (c = 0.18,CHC13). 'H NMR (CDC13): 6 7.65H, 5.03; N, 8.74.Found: Anal. Calcd for C23H16N2: C, 86.22; 7.58(m, 2 a r H), 7.44-7.33(m, 10 ar H), 7.10-6.88(m, 11 a r C, 85.56; H, 5.12; N, 8.64. H), 6.12(d, J = 2.2,pz CH), 6.01 (dq, J = 6.9,J = 3.5, General Method for the Preparation of P,NLigands CHMeN), 5.38(s, trp CHI, 4.90(m, cp H), 4.50(m, cp HI, 4.09 (3). A solution of a n R*PFA (1)and a 1H-pyrazole (2)(1-14 (s, 5 cp H), 4.00(m, cp H), 2.10(d, J = 6.9, CHMeN). 13C{1H} equiv) in 1-3 mL of glacial acetic acid was stirred a t 70-80 146.3,145.7(ar C), 139.2-122.7(ar NMR (CDCl3): 6 147.3, "C for 3-9 h. The orange to red reaction mixture was C, a r CH), 107.1(pz CH), 93.5(cp C), 75.8(cp C), 71.6(cp CHI, quenched with excess saturated aqueous sodium bicarbonate 70.1(cp CH), 69.8(cp CH), 69.6(5 cp CHI, 55.7(CHMeN), 21.8 and extracted three times with dichloromethane. The com(CHMeN). 31P{1H} NMR (CDC13): 6 -26.0(SI. IR (cm-'1: bined organic layers were washed with brine, dried over 1519,1456,1434,1247,1220,1168,1106,1055,916,821,749, magnesium sulfate, and filtered. Solvent was removed by 697,631. MS ( m l z ) : 716 (M+), 651 (M+ - CP), 441,397 (M' rotary evaporation, and the crude product thus obtained was - Hpz), 331 (397- cp), 320 (Hpz+),289,252 (trp'), 212 (M+ purified by flash column chromatography as detailed below, - Hpz - PPh2, loo%), 183,121 (Fe-cp+). Anal. Calcd for filtered over alumina to remove phosphine oxides, recrystalC4,H3,FeNzP*CH2C12: C, 71.92;H, 4.90; N, 3.49.Found: C, lized, and dried in uucuo. 71.95; H, 5.14; N, 3.46. 1-{(S)-l-[(R)-2-(Diphenylphosphino)ferrocenyllethyl}1-{(S)-l-[(R)-2-(Diphenylphosphino)ferrocenyllethyl}liY-pyrazole (3aa): from la (441 mg, 1 mmol) and 333,5-dimethyl-lH-pyrazole (3ae): from la (2.5g, 5.6mmol) diphenyl-W-pyrazole (2a)(136mg, 2mmol, 2equiv), according and 3,5-dimethyl-W-pyrazole (2e) (0.65g, 6.8mmol, 1.2 to the general method. FC (silica, hexane/ethyl acetate 1/1, equiv), according to the general method. Yield: 1.52g (55%). = +363 1% NEt3): yield 300mg (64%).Mp: 131 "C dec. Mp: 127 "C dec. [a]% = +329 (c = 0.42,CHC13). 'H NMR (c = 0.50, CHC13). 'H NMR (CDC13): 6 7.56-7.26(m, 5 ar H), J = 2.6, (CDC13):6 7.53-6.68(m, 10 a r H), 5.58 (dq, J = 6.9, 7.15(m, 2 pz CH), 7.06-6.95(m, 5 a r H), 5.77(dq, J = 2.6, J CHMeN), 5.06(s, pz CHI, 4.80(m, cp H), 4.36(m, cp H), 4.05 = 6.9, CHMeN), 5.58 (m, pz CHI, 4.78(m, cp H), 4.40(m, cp (s, 5 cp HI, 3.73(m, cp HI, 2.13(s, pzMe), 1.95(s, pzMe), 1.70 H), 4.05(s, 5 cp H), 3.85 (m, cp H), 1.92(d, J = 6.9Hz, (d, J = 6.9, CHMeN). 13C{1H}NMR (CDC13): 6 150-120 (10 CHMeN). 13C{'H} NMR (CDC13):6 150-120 (10a r CH), 113.1 a r CH), 103.9(pz CHI, 94.0(cp C), 70.3(2cp CHI, 69.5(5 cp (3pz CH), 69.8(2cp CH), 69.6(5 cp CHI, 69.3(cp CH), 55.5 CH), 69.2(cp CHI, 51.5(CHMeN), 20.3 (CHMeN), 13.4(pzMe), (CHMeN), 21.0(CHMeN). 31P{1H}NMR (CDC13):6 -24.0(s). 10.9(pzMe). 31P{1H}NMR (CDC13): 6 -24.1(s). MS ( m l z ) : MS ( m / z ) :464 (M+, loo%), 396 (M+ - Hpz), 331 (396- CP), 492 (M+),396 (M+ - Hpz), 331 (396- cp), 276 (331- Fe), 56 276 (331- Fe). Anal. Calcd for C27Hz5FeNzP: C, 69.84;H, (Fe, 100%). Anal. Calcd for CzgHzgFeNzP: C, 70.72;H, 5.96; 5.43;N, 6.03.Found: C, 69.68; H, 5.36; N, 5.97. H, 6.01;N, 5.59. 1-{~S~-l-[(R)-2-(Diphenylphosphino)ferrocenyllethyl}-N, 5.69.Found: C, 70.74; 1-{(S)-l-[(R)-2-(Diphenylphosphino)ferrocenyllethyl}3-phenyl-1H-pyrazole (3ab):from la (300mg, 0.68mmol) 5-methyl-3-(trifluoromethyl)-1H-pyrazole (3af):from la and 3-phenyl-1H-pyrazole (2b)(118mg, 0.82mmol, 1.2equiv), (441mg, 1 mmol) and 3-methyl-5-(trifluoromethyl)-W-pyraaccording to the general method. FC (silica, hexane/ethyl zole (2f)(150mg, 1 mmol), according to the general method. = +303 acetate 5/11:yield 150mg (41%). Mp: 122 "C. [a123~ Yield: 188 mg (35%). Mp: 148 "C. [ a I z 3=~+282 (e = 0.66, (c = 0.50, CHC13). 'H NMR (CDC13): 6 7.65-7.56 (m, 4 a r H), CHC13). 'H NMR (CDC13): 6 7.53-6.61(m, 10 ar H), 5.72(dq, 7.41-7.23(m, 6 a r H), 7.02(d, J = 2.3,pz CH), 6.97-6.79(m, J = 6.9, J = 2.6,CHMeN), 5.52 (s, pz CHI, 4.82(m, cp HI, 5 a r HI, 5.92(d, J = 2.3,pz CHI, 5.86(dq, J = 6.9, J = 3.2, 4.38(m, cp HI, 4.08(s, 5 cp HI, 3.75(m, cp HI, 2.16(s, pzMe), CHMeN), 4.80(m, cp H), 4.43(m, cp H), 3.90(m, cp H), 4.11 1.84(d, J = 6.9, CHMeN). 13C{1H}NMR (CDC13): 6 135-127 (s, 5 cp HI, 1.99(d, J = 6.9, CHMeN). 13C{1H}NMR (CDC13):

Organometallics, Vol. 14,No. 11,1995 5421

Pyrazole-Containing Ferrocenyl Ligands

CH), 70.7(cp CHI, 69.5(5 cp CHI, 69.1(cp CH), 52.1(CHMeN), 20.7(CHMeN), 11.0(pzMe). 31P{1H} NMR (CDC13): 6 -23.9 (a). MS ( m / z ) : 554 (M+, loo%), 489 (M+ - CP), 396 (M+ Hpz), 331 (396- cp), 276 (331- Fe). Anal. Calcd for C34H31FeNZP C, 73.65; H, 5.64; N, 5.05. Found: C, 73.52; H, 5.85; N, 4.94. 1-{(S)-l-[(R)-2-(Diphenylphosphino)ferrocenyllethyl}5-methyl-3-(2-pyridyl)-lH-pyrazole (3ak):from la (300mg, 0.68mmol) and 5-methyl-3-(2-pyridyl)-lu-pyrazole (2k)(130 mg, 0.82mmol, 1.2equiv), according to the general method. FC (silica, hexane/ethyl acetate 2/11: yield 242 mg (64%). Mp: 130 "C. [aIz3~ = +330 (c = 0.74,CHC13). 'H NMR (CDCL): 6 8.50 (m, py CHI, 7.81(m, py CH), 7.62-7.46(m, 3 a r H), 7.30(m, 3 ar HI, 7.04-6.67 (m, 6 a r HI, 6.01(s, PZ CH), 5.69(dq, J = 6.9,J = 2.9,CHMeN), 4.82(m, CP HI, 4.34(m, cp H), 4.06(s, 5 cp H), 3.73(m, cp HI, 2.15(s, pzMe), 1.87(d, J = 6.9, CHMeN). 13C{lH}NMR (CDC13): 6 152.9(py C), 149.5 (ar C), 148.6(py CH), 137.9-126.8 (ar C, ar CH), 121.2,119.6 (py CHI, 103.1(pz CHI, 93.4(cp C), 75.4(cp C), 71.2(CP CH), 70.6(cp CH), 69.5(5 cp CHI, 69.0(cp CHI, 52.4(CHMeN), 20.7 (CHMeN), 11.0(pzMe). 31P{1H} NMR (CDC13): 6 -24.1 (9). IR (cm-I): 1592,1499,1426,1246,1204,1106,824,784,744, EA is obtained. 1-{(S)-l-[(R)-2-(Diphenylphosphino)ferrocenyllethyl}- 699. MS ( m l z ) : 555 (M+),490 (M+ - cp, loo%), 396 (M+ Hpz), 331 (396- cp), 305,279,214. Anal. Calcd for C33H305-methyl-3-cyclohexy1-lH-pyrazole (3ah): from la (300 FeN3.CHzC12: C, 63.77; H, 5.04; N, 6.56.Found: C, 64.35; H, mg, 0.68mmol) and 5-methyl-3-cyclohexy1-lH-pyrazole (2h) 4.96; N, 6.60. (134 mg, 0.82 mmol, 1.2equiv), according to the general 1-{(S)-l-[(R)-2-(Diphenylphosphino)ferrocenyllethyl}method. FC (silica, hexane/ethyl acetate lO/l,2% NEt3): yield 5-methy1-3-(3-pyridyl)-lH-pyrazole (3al):from la (300mg, = +297 (c = 0.39, CHCL). 100 mg (26%). Mp: 94 "C. [aIz3~ 0.68mmol) and 5-methyl-3-(3-pyridyl)-lH-pyrazole (21)(118 lH NMR (CDC13): 6 7.54(m, 2 ar H), 7.37(m, 3 ar HI, 7.10mg, 0.75mmol, 1.1equiv), according to the general method. J = 2.9, 6.95(m, 3 a r H), 6.71(m, 2 a r H), 5.62(dq, J = 6.9, FC (silica, hexane/ethyl acetate 2/1,2% NEt3): yield 122 mg CHMeN), 5.23(5, pz CHI, 4.81(m, cp H), 4.37(m, cp H), 4.04 (32%). Mp: 167 "C. = +294 (c = 0.56, CHC13). 'H (s, 5 cp H), 3.79(m, cp H), 2.47(m, Cy CH), 2.10(s, pzMe), NMR (CDC13): 6 8.76,8.44(m, py CHI, 7.87(m, py CH), 7.48 1.86(d, J = 6.9, CHMeN), 1.83-1.62(m, 4 Cy CHI, 1.42-0.86 (m, 6 Cy CH). 13C{lH} NMR (CDC13): 6 156.7, 136.8-127.0, (m, 2 ar H), 7.32(m, 3 ar HI, 7.20(m, a r H), 6.90-6.65(m, 5 a r H), 5.70(dq, J = 6.9,J = 2.9,CHMeN), 5.61( 6 , pz CH), 117.6(10a r CHI, 101.0(pz CHI, 94.7(cp C), 78.0(cp C), 71.4 4.83(m, cp HI, 4.37(m, cp HI, 4.08(s, 5 cp HI, 3.73(m, CP HI, (cp CH), 70.8(cp CH), 69.8(5 cp CHI, 69.6(cp CHI, 52.0 2.18(s, pzMe), 1.88(d, J = 6.9,CHMeN). 13C{lH} NMR (CHMeN), 37.4 (Cy CHI, 33.6,26.5,26.3 (CY CHI, 20.9 (CDCl3): 6 148.7(ar C), 147.6,146.8(py CHI, 146.2,138.0, (CHMeN), 11.5 (pzMe). 31P{1H} NMR (CDCl3): 6 -23.8(9). IR (cm-I): 1654,1550, 1434,1247,1170,1106,1038,818,743, 135.0-126.7(ar-C, ar CHI, 122.9(py CHI, 101.7(pz CHI, 93.1 (cp C), 75.8(cp C), 71.3(cp CH), 70.6(cp CHI, 69.5(5 cp CHI, 696. MS ( m l ~ )560 : (M+, loo%),545 (M+ - CH3), 495 (M+ 69.2(cp CHI, 52.4(CHMeN), 20.5(CHMeN), 11.0(PzMe). 31Pcp), 396 (M+ - Hpz), 360,331 (396- cp), 276 (396- Fe-cp), {lH} NMR (CDCl3): 6 -24.5(s). IR (cm-'): 1547,1475,1432, 253, 212,183,164 (Hpz+). Anal. Calcd for C34H37FeN2P1371,1312,1248,1182,1170,1127,1105,1043,1027,1002, 0.5CHzC12: C, 68.72; H, 6.35; N, 4.65.Found: C, 68.65; H, 829,772,742,696. MS ( m l z ) : 555 (M+, loo%), 540 (M+ 6.29;N, 4.55. 1-{(S)-l-[(R)-2-(Diphenylphosphino)ferrocenyllethyl}- CH3), 490 (M+ - CP),396 (M+ - Hpz), 370,355,331 (396cp), 276 (396- Fe-cp), 183.Anal. Calcd for C33H30FeN3P: C, 5-methyl-3-ethoxy-lH-pyrazole (3ai):from la (441mg, 1 N, 7.54. 71.36; H, 5.44;N, 7.57.Found: C, 71.34;H, 5.16; mmol) and 3-methyl-5-ethoxy-VI-pyrazole (2i)(189mg, 1.5 1-{(S)-l-[(R)-2-(Diphenylphosphino)ferrocenyllethyl}mmol, 1.5equiv), according to the general method. FC (silica, 5-methyl-3-(4-pyridyl)-lH-pyrazole (3am): from la (300 hexane/ethyl acetate 5/1,2% NEt3): yield 125 mg (24%). Mp: mg, 0.68mmol) and 5-methyl-3-(4-pyridyl)-1H-pyrazole (2m) = +293 (c = 0.195, CHC13). lH NMR (CDC13): 116 "C. [aIz3~ 67.53-6.71(m,lOarH),5.46(dq,J=6.9,J=2.6,CHMeN),(130mg, 0.82mmol, 1.2 equiv), according to the general method. FC (silica, diethyl ether, 2% NEt3): yield 140 mg 4.77(m, cp H), 4.73(s, pz CHI, 4.33(m, cp HI, 4.05(s, 5 CP HI, (37%) as orange crystals (from dichloromethanehexane). 3.84(2q, J = 6.9,diast E t CHd, 3.68(m, cp HI, 2.06(s, pzMe), Mp: 158 "C. [ a ] 2 3 ~ = +365 (CHC13, c = 0.44). lH NMR 1.79(d, J = 6.9, CHMeN), 1.29(t, J = 6.9,Et CH3). 13C{lH} (m, 4 a r HI, 7.35(m, (CDC13): 6 8.51(m, 2 py CHI, 7.50-7.42 NMR (CDC13): 6 138-127 (10a r CHI, 88.1(pz CHI, 71.0(CP 3 a r H), 6.91-6.64 (m, 5 ar H), 5.72 (dq, J = 6.9, J = 2.9, CH), 70.8(cp CHI, 69.6(5 cp CH), 69.5(cp CH), 64.3(Et CHd, CHMeN), 5.66(s, pz CH), 4.83(m, cp HI, 4.39(m, CP €9, 4.10 51.5(CHMeN), 20.6(CHMeN), 14.9(Et CH3), 10.8(pzMe). 31P(s, 5 cp H), 3.74(m, cp HI, 2.19(s, pzMe), 1.88(d, J = 6.9, {'H} NMR (CDC13): 6 -23.6(SI. MS ( m l z ) : 522 (M+, loo%), CHMeN). 13C{lH} NMR (CDCl3): 6 149.5(py CHI, 146.5, 493 (M+ - Et), 457 (M+ - CP), 396 (M+ - Hpz), 331 (396141.3,138.2-126.9 (ar C, ar CHI, 119.5(py CH), 102.3(PZ CHI, cp), 276 (331- Fe). Anal. Calcd for C ~ O H ~ I F ~ N ZC, O 68.24; P: 93.1(cp C), 75.5(cp C), 71.3(CP CHI, 70.6(CP CHI, 69.5(5 CP H, 5.98;N, 5.36. H, 5.91; N, 4.99.Found: C, 68.97; I-{(@I-[ (R)-2-(Diphenylphosphino)ferrocenyllethyl}- CH), 69.1(cp CH), 52.6(CHMeN), 20.5(CHMeN), 11.0(pzMe). 31P{1H} NMR (CDC13): 6 -24.5(s). IR (cm-l): 1603,1433, 5-methyl-3-phenyl-lH-pyrazole (3aj):from la (300mg, 0.68 MS ( m l z ) : 555 (M+, loo%), 490 (M+ 1247,1106,747,698. mmol) and 3-methyl-5-phenyl-1H-pyrazole (2j)(129mg, 0.82 cp), 396 (M+ Hpz), 370,355,331 (396- cp), 276 (396- Femmol, 1.2equiv), according to the general method. FC (silica, cp), 253,183.Anal. Calcd for C ~ ~ H ~ O F ~ N ~ C, P C63.77; H~C~~: hexane/ethyl acetate 5/11: yield 208 mg (55%). Mp: 171 "C H, 5.02; N, 6.42. H, 5.04;N, 6.56.Found: C, 63.64; dec. = 1338 (c = 0.45, CHC13). 'H NMR (CDC13): 6 1-{(S)1 [(R) -2(Diphenylphosphino)ferrocenyllethyl} 7.61-6.68(m, 15 ar H), 5.66(dq, J = 6.9, J = 2.9,CHMeN), 3-(2,4-dimethoxyphenyl)-5-methyl-lH-pyrazole (3-): from 5.61(5, pz CHI, 4.85(m, cp HI, 4.38(m, cp HI, 4.09(s, 5 CP HI, la (300mg, 0.68mmol) and 3-(2,4-dimethoxyphenyl)-5-methyl3.74(m, cp H), 2.15(s, pzMe), 1.91(d, J = 6.9, CHMeN). 13C1H-pyrazole (2n)(178mg, 0.82mmol, 1.2equiv), according to 138.0, 137.6,136.9 (ar C), 135.0{'H} NMR (CDC13): 6 149.3, the general method. FC (silica, hexane/ethyl acetate 511): 125.2(ar CH), 101.6(pz CH), 93.7(cp C), 75.2(cp C), 71.2(cp

(10ar CH), 102.8(pz CH), 71.7(CP CHI, 70.9(CPCH), 70.1(cp CH), 69.9(5 cp CHI, 53.5 (CHMeN), 20.7(CHMeN), 10.9 (pzMe). 31P{1H}NMR (CDCl3): 6 -24.7(8). MS ( m / z ) : 562 (M+), 396 (M+ - Hpz), 331 (396- cp), 276 (331- Fe, 100%). Anal. Calcd for CzgH26F3FeNzP: C, 63.62;H, 5.03;N, 5.02. Found: C, 63.75; H, 4.80; N, 5.13. 1-{ (S)1 [(R) -2(Dipheny1phosphino)fel~ocenyll ethyl} 5-methyl-3-isopropyl-lH-pyrazole (3ag):from la (662mg, 1.50mmol) and 3-methyl-5-isopropyl-VI-pyrazole (2g)(280 mg, 2.25mmol, 1.5equiv), according to the general method. FC (silica, hexane/ethyl acetate 4/11:yield 205 mg (red oil, = +256 (c = 0.16, CHC13). lH NMR (CDC13): 6 26%). [a123~ 7.80-6.60(m, 10 ar H), 5.61(dq, J = 6.9, J = 2.6,CHMeN), 5.20(s, pz CHI, 4.78(m, cp HI, 4.34(m, cp H), 4.04(s, 5 CP H), 3.80(m, cp H), 2.75(st, J = 6.1,'Pr CH), 2.09(8, pzMe), 1.84 (d, J = 6.9,CHMeN), 1.05(d, J = 6.1,2 'Pr CH3). 13C{lH} NMR (CDC13): 6 135-125 (10ar CHI, 100.4(pz CHI, 71.4(cp CHI, 70.4(cp CHI, 69.5(5 cp CHI, 69.2(cp CH), 51.8(CHMeN), 27.3('Pr CH), 22.9(2'Pr CH3), 20.5(CHMeM, 11.1(pzMe). 31P{1H}NMR (CDC13): 6 -23.9(9). MS ( m l z ) :520(M+),396 (M+ - Hpz), 331 (396- cp), 109 (pz - Me, 100%). No correct

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Burckhardt et al.

5422 Organometallics, Vol. 14,No. 11, 1995

IR (cm-'): 1546,1434,1416,1318,1247,1168,1106,1013, 888,823,799,734,721,695. MS ( m / ~ )654 : (M+),639(M+ CH3), 589 (M+ - CP), 396 (M+ - Hpz), 331 (396 - CP), 275 H),6.51(m,2arH),5.83(s,pzCH),5.65(dq,J=6.8,J=2.9,(396 - Fe-cp), 258 (Hpzf, 100%). Anal. Calcd for C42H35FeN2P: C, 77.07; H, 5.39;N, 4.28.Found: C, 77.20;H, 5.33; CHMeN), 4.87(m, cp H), 4.39(m, cp H), 4.09(s, 5 cp H), 3.75 N, 4.22. (m, cp H), 2.15(s, pzMe), 1.91(d, J = 6.8, CHMeN). 13C{1H} 1-{(S)-l-[ (R)-2-(Diphenylphosphino)ferrocenyllethyl}NMR (CDC13): 6 159.5,157.3(Ph-COMe), 146.1, 136.6-126.8 5-(9-anthryl)-3-methyl-lH-pyrazole (3aq'): regioisomer of (ar C, a r CH), 116.5(Ph C), 104.9,104.5,98.3(2Ph CH, pz 3aq (for synthesis see above). FC (silica, hexanddiethyl ether CH), 94.1(cp C), 74.9(cp C), 71.1(cp CH), 70.8(cp CHI, 69.4 5/1):yield 53 mg (7%). Mp: 217 "C. [aIz3~ = +265 (c = 0.36, (5 cp CH), 69.1(cp CH), 55.1(CHMeN), 20.8(CHMeN), 11.0 CHC13). 'H NMR (CDC13): 6 8.52(9, ar H), 8.02(m, a r HI, (pzMe). 31P{1H}NMR (CDC13): 6 -23.9(s). IR (cm-l): 1613, 7.59(d, J = 8.8, ar HI, 7.51-7.27(m, 10 a r HI, 7.11-6.99(m, 1583,1517,1465,1432,1302,1280,1247,1208,1159,1037, 3 a r H), 6.90-6.84(m, 2 ar HI, 6.01(s, pz CH), 5.10(dq, J = 822,742,697. MS ( m l z ) : 614(M+), 549 (M+ - CP), 396 (M+ 6.9, J = 2.4,CHMeN), 4.12(m, cp H), 4.00(m, cp HI, 3.82(s, - Hpz, loo%), 331 (396 - cp), 288,252,218 (Hpz+). Anal. 5 cp H), 3.76(m, cp H), 2.28(s, pzMe), 1.68(d, J = 6.9, Calcd for C36H35FeN202P: C, 70.36;H, 5.74; N, 4.56.Found: CHMeN). I3C{lH} NMR (CDCl3): 6 146.4,140.1, 138.2,137.9, C, 70.63; H, 5.96;N, 4.28. 1-{(S)-1-[ (R)-2-(Diphenylphosphino)ferrocenyl]ethyl}- 135.3-124.6(ar C, a r CHI, 108.7(pz CHI, 95.5(cp C), 74.2 (cp C), 70.7(cp CH), 69.5(cp CH), 68.7(cp CHI, 69.3(5cp 5-methyl-3-( 1-naphthyl)-lH-pyrazole (3ao): from la (300 CHI, 53.7 (CHMeN), 21.8 (CHMeN), 13.6(pzMe). 31P{1H1 mg, 0.68mmol) and 5-methyl-3-(a-naphthyl)-lH-pyrazole (20) 1367, NMR (CDCl3): 6 -24.0(s). IR (cm-I): 1625,1540,1432, (212mg, 1.02mmol, 1.5 equiv), according to the general 1164,1108,890,822,739,699. MS ( m / z ) : 654 (M+, loo%), method. FC (silica, hexane/ethyl acetate 6/1):yield 183 mg 589 (M+ - CP), 454,396(M+ - Hpz), 378,331(396- CP), 275 (45%). Mp: 192 "C dec. [ a I z 3 = ~ +386 (c = 0.45, CHC13). 'H (396 - Fe-cp), 258 (Hpz+). Anal. Calcd for C42H35FeNzPNMR (CDC13): 6 8.52(m, a r HI, 7.76(m, ar H), 7.56-7.38 (m, 0.5H20: C, 75.00; H, 5.54; N, 4.17.Found: C, 75.06; H, 5.47; 9 a r H), 6.94-6.79(m, 5 a r H), 6.51(m, 2 a r H), 5.75(dq, J = N, 4.15. 6.9, J = 3.1,CKMeN), 5.69(s, pz CHI, 4.93(m, cp HI, 4.43 1-{(R)-1-[ (S)-2-(Diphenylphosphino)ferrocenyllethyl}(m, cp H), 4.12(s, 5 cp H), 3.80(m, cp H), 2.25(s, pzMe), 1.98 3-ferrocenyl-5-methyl-I+l-pyrazole (3ar): from la' (300 (d, J = 6.9, CHMeN). 13C{1H}NMR (CDC13): 6 149.2, 138.0mg, 0.68mmol) and 3-ferrocenyl-5-methy1-1H-pyrazole(2r) 125.0(ar C, a r CH), 116.5(ar C), 104.9(pz CHI, 94.4(cp C), (218 mg, 0.82 mmol, 1.2 equiv), according to the general 73.8(cp C), 71.1(cp CHI, 70.8(2cp CH), 69.5(5 cp CHI, 51.9 method. FC (silica, hexaneholuene or diethyl ether 4/1,2% (CHMeN), 21.0(CHMeN), 11.0(pzMe). 31P{1H}NMR (CDC13): NEt3): yield 80 mg (18%). Mp: 163 "C dec. [a]'% = -283 (c 6 -23.9(5). IR (cm-I): 1549,1433,1418,1370,1318,1248, = 0.36,CHCl3). 'H NMR (CDC13): 6 7.56-7.48(m, 2 a r H), MS ( m l z ) : 604(M+, 1108,1002,822,804,792,778,743,696. 7.38(m, 3 a r H), 7.12-6.92(m, 3 ar H), 6.75(m, 2 a r H), 5.54 loo%), 589 (M+ - CH3), 539 (M+ - CP),396 (M+ - Hpz), 331 (dq,J=6.8,J=2.8,CHMeN),5.47(s,pzCH),4.75(m,cpH), (396- cp), 302,276 (396- Fe-cp), 208 (Hpz+). Anal. Calcd 4.48(m, 2 cp H), 4.34(m, cp H), 4.15(m, 2 cp H), 4.07(s, 5 cp for C38H33FeN2P: C, 75.50; H, 5.50; N, 4.63.Found: C, 75.52; H), 3.98(m, 5 cp H), 3.75(m, cp HI, 2.03(s, pzMe), 1.92(d, J H, 5.31;N, 4.60. = 6.8, CHMeN). 13C{1H}NMR (CDC13): 6 147.8, 138.7-126.9 1- { ( S ) 1 [( R)-2(Diphenylphosphino)ferrocenyll ethyl} (ar C, a r CHI, 102.4(pz CHI, 94.4(cp C), 74.8,72.3(cp C), 5-methyl-3-(2-naphthyl)-lH-pyrazole (3ap):from la (300 70.0(cp CHI, 69.5(5 cp CH), 69.0(5 cp CHI, 67.4(4cp CHI, mg, 0.68mmol) and 5-methyl-3-(/?-naphthyl)-lH-pyrazole (2p) 66.6(4cp CHI, 51.8(CHMeN), 21.0(CHMeN), 10.9(pzMe). (212 mg, 1.02mmol, 1.5equiv), according to the general 31P{1H} NMR (CDCl3): 6 -23.8(s). IR (cm-I): 1568,1433, method. FC (silica, hexane/toluene or diethyl ether 5/1,2% 1404,1248,1105,1001,821,748,821,696. MS ( m l z ) : 662 = +337 (c = NEt3): yield 114 mg (28%). Mp: 129 "C. [a123~ (M+), 397 (M+ - Hpz), 347,331 (397- CP), 266 (HPz+),212 0.34,CHC13). 'H NMR (CDC13): 6 8.02(d, J = 0.8, ar H), (M+ - Hpz - PPh2, loo%), 121 (Fe-cp+). Anal. Calcd for 7.88-7.82(m, 4 ar H), 7.58-7.36(m, 7 a r H), 6.90-6.73(m, 5 C38H3SFe2N2P: C, 68.91;H, 5.33;N, 4.23.Found: C, 68.91; a r H), 5.76(s, pz CHI, 5.75(dq, J = 6.9,J = 3.1,CHMeN), H, 5.44;N, 4.15. 4.93(m, cp HI, 4.43(m, cp HI, 4.14(s,5 cp HI, 3.78(m, cp HI, 1-{(S)-l-[(R)-2-(Diphenylphosphino)ferrocenyllethyl}2.22(s, pzMe), 1.96(d, J = 6.9,CHMeN). 13C{'H) NMR 3,4,5-trimethyl-lH-pyrazole(3as): from la (441 mg, 1 (CDC13): 6 149.2, 138.0-123.2(ar C, ar CHI, 101.9(pz CHI, mmol) and 3,4,5-trimethyl-lH-pyrazole (2s)(110mg, 1 mmol), 93.6(cp C), 75.4(cp C), 71.3(cp CHI, 70.7(cp CH), 69.5(5cp according to the general method. Yield: 205 mg (40%). [a]% CH), 69.1(cp CHI, 52.3(CHMeN), 20.6(CHMeN), 11.1(pzMe). = $310 (c = 0.27, CHC13). 'H NMR (CDC13): 6 7.50-6.73(m, 31P{1H} NMR (CDC13): 6 -23.9(SI. IR (cm-l): 1630,1550, 10 a r H), 5.63(dq, J = 6.8, J = 2.5, CKMeN), 4.80(m, cp HI, 1433,1416,1385,1318,1247,1169,1126,1106,1044,1000, 4.34(m, cp HI, 4.08(s, 5 cp HI, 3.67(m, cp HI, 2.01(s, pzMe), 858,821, 779,743,697.MS ( m / z ) :604(M+, loo%),589 (M+ 1.87(s, pzMe), 1.80(d, J = 6.8, CHMeN), 1.36(s, pzMe). I3C- CH3), 539 (M+ - CP), 396 (M+ - Hpz), 331 (396- CP), 302, {'H} NMR (CDC13): 6 140-127 (10 a r CH), 71.7(cp CHI, 70.6 276 (396- Fe-cp), 208 (Hpz+). Anal. Calcd for C38H33FeN2P: (cp CH), 70.3(cp C), 69.8 (5 cp CH), 69.2(cp CHI, 52.0 C, 75.50; H, 5.50; N, 4.63.Found: C, 75.60; H, 5.34; N, 4.43. I-{(S)-l-[(R)-2-(Diphenylphosphino)ferrocenyllethyl}- (CHMeN), 20.4(CHMeN), 11.9(pzMe), 9.7(pzMe), 7.6(pzMe). 3'P{lH) NMR (CDC13): 6 -24.2(9). MS ( m / ~ )506 : (M'), 396 3-(9-anthryl)-5-methyl-lH-pyrazole (3aq): from la (513 (M+ - Hpz), 331 (396- cp), 276 (331- Fe), 149(100%). Anal. mg, 1.16mmol) and 3-(9-anthryl)-5-methyl-lH-pyrazole (2q) H, 6.17; N, 5.53. Found: C, Calcd for C30H31FeN2P: C, 71.17; (360 mg, 1.39 mmol, 1.2equiv), according to the general 71.26; H, 6.30;N, 5.60. method, yielding a 5:l mixture of the two regioisomers 3aq 1-{(S)-l-[(R)-2-(Diphenylphosphino)ferrocenyllethyl}and 3aq' (see below). FC (silica, hexane/diethyl ether 5/11: 3,5-dimethyl-4-nitro-lH-pyrazole (3at):from la (157 mg, yield 280 mg (37%). Mp: 202 "C dec. [ a l Z 3= ~ +338 (e = 0.35mmol) and 3,5-dimethyl-4-nitro-lH-pyrazole (2t)(157mg, 0.24, CHC13). 'H NMR (CDC13): 6 8.43(5, a r H), 7.98(d, J = 0.39mmol, 1.1 equiv), according to the general method. FC 9.4, a r H), 7.67-7.60(m, 2 a r HI, 7.47-7.32 (m, 7a r HI, 7.10(silica, hexandethyl acetate 3/1,2%NEt3): yield 120mg (63%). 6.94(m, 5 a r H), 5.85(dq, J = 6.9, J = 3.3,CHMeN), 5.81(s, Mp: 163 "C. [a123D = +296 (c = 0.175,CHCld. 'H NMR pz CH), 4.93(m, cp H), 4.42(m, cp H), 4.08(s, 5 cp HI, 3.91 J = 2.5, (CDCl3): 6 7.47-6.75(m, 10 ar H), 5.74(dq, J = 6.9, (m, cp HI, 2.32(s, pzMe), 2.09(d, J = 6.9, CHMeN). 13C{1H} CHMeN), 4.78(m, cp H), 4.40(m, cp H), 4.13(s, 5 cp HI, 3.73 NMR (CDC13): 6 146.6,139.4,137.2,135.4-124.6(ar C, a r (m, cp H), 2.52 ( 8 , pzMe), 2.19(s, pzMe), 1.82(d, J = 6.9, CH), 107.9(pz CH), 94.6(cp C), 74.6(cp C), 71.0(cp CHI, 70.9 CHMeN). '3C{'H} NMR (CDC13): 6 140-127(10a r CH), 72.2 (cp CH), 69.8(cp CH), 69.5(5 cp CHI, 51.9(CHMeN), 21.6 (cp CHI, 70.2(cp CHI, 69.9(5 cp CHI, 69.6(CP CHI, 53.6 (CHMeN), 11.2(pzMe). 31P{1H} NMR (CDC13): 6 -24.2(SI.

yield 80 mg (19%). Mp: 83 "C. = +314 (c = 0.54, CHC13). 'H NMR (CDC13): 6 7.70(d, J = 8.4, a r H), 7.54(m, 2 a r H), 7.38(m, 3 a r H), 6.95-6.80(m, 3 a r H), 6.71(m, 2 a r

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Organometallics, Vol. 14,No. 11, 1995 5423

Pyrazole-Containing Ferrocenyl Ligands (CHMeN), 19.7 (CHMeN), 14.3 (pzMe), 11.6 (pzMe). 31P{1H} NMR (CDC13):6 -26.1 (s). IR (KBr): 3068,3049, 2977,2932, 1560,1489,1458,1433,1360. MS ( m / z ) :537 (M+, loo%), 491 (M+ - NOz), 396 (M+ - Hpz), 331 (396 - cp), 276 (331 - Fe). Anal. Calcd for C2sH28FeNsOzP: C, 64.82; H, 5.25; N, 7.82. Found: C, 64.97; H, 5.40; N, 7.79. 1-{@)-I-[ (R)-2-(Diphenylphosphino)femenyllethyl}4-bromo-3,5-dimethyl-lH-pyrazole (3au): from la (441mg, 1mmol) and 4-bromo-3,5-dimethyl-lH-pyrazole (2u)(364 mg, 2 mmol, 2 equiv), according to the general method. Yield: 352 mg (62%). Mp: 150 "C dec. [a123~ = +284 (c = 0.505, CHC13). 'H NMR (CDC13): 6 7.53-6.61 (m, 10 a r H), 5.63 (dq, J = 6.9, J = 2.5, CHMeN), 4.78 (m, cp H), 4.38 (m, cp H), 4.09 (s, 5 cp H), 3.73 (m, cp H), 2.10 (s, pzMe), 1.89 (s, pzMe), 1.78 (d, J = 6.9, CHMeN). W{lH} NMR (CDCl3): 6 150-120 (10 ar CHI, 71.6 (cp CH), 70.4 (cp CHI, 69.6 (5 cp CH), 69.1 (cp CHI, 53.3 (CHMeN), 20.0 (CHMeN), 12.0 (pzMe), 11.6 (pzMe). 31P{1H} NMR (CDC13): 6 -25.0 (s). MS ( m / z ) : 570 (M+, loo%), 491 (M+ - Br), 396 (M+ - Hpz), 331 (396 - cp), 276 (331 - Fe), 183. Anal. Calcd for CzsH28BrFeNzP: C, 60.97; H, 4.94; N, 4.90. Found: C, 60.89; H, 4.89; N, 4.86. 1-{(S)-1 [( R )-2-(Diphenylphosphino)ferrocenyllethyl} 3,5-bis(trifluoromethyl)-lH-pyrazole (3av):from la (441 mg, 1mmol) and 3,5-bis(trifluoromethyl)-lH-pyrazole(2v)(205 mg, 1 mmol), according to the general method. FC (silica, hexane/ethyl acetate lO/l, 2% NEt3): yield 210 mg (35%). Mp: 125 "C dec. [ a ] 2 3= ~ f 1 5 4 (c = 0.465, CHC13). 'H NMR (CDC13): 6 7.51-6.75 (m, 10 ar H), 6.26 (s, pz CHI, 5.97 (dq, J = 6.9, J = 2.5, CHMeN), 4.81 (m, cp H), 4.44 (m, cp H), 4.15 (s, 5 cp H), 3.73 (m, cp H), 1.94 (d, J = 6.9, CHMeN). 13C{lH} NMR (CDC13):6 138-127 (10 ar CHI, 104.9 (pz CHI, 90.4 (cp CH), 71.8 (cp CH), 71.1 (cp CH), 69.7 (5 cp CHI, 69.5 (cp CHI, 56.7 (CHMeN), 22.5 (q,, J = 549, pzCF3), 21.2 (CHMeN). l9F{'HI NMR (CDC13): 6 -58.9 (d, J = 21, PzCF~),-62.2 (s, pzCF3). 31PNMR (CDC13): 6 -25.5 (9, J = 21). MS ( m l z ) : 600 (M+, loo%), 396 (M+ - Hpz), 276 (396 - Fe-cp), 183,166, 121. Anal. Calcd for C2sHz3F6FeN2P: C, 58.02; H, 3.86; N, 4.67. Found: C, 56.44; H, 3.80; N, 4.50. 1-{(S).1-[(R)-2-(Diphenylphosphino)ferrocenyllethyl}3,5-bis(isopropyl)-lH-pyrazole(3aw):from la (574 mg, 1.3 mmol) and 3,5-isopropyl-lH-pyrazole (2w)(2.80 g, 18.4 mmol, 14 equiv), according to the general method. FC (silica, toluene/ diethyl ether 9/1,2% NEt3): yield 308 mg (43%). Mp: 130 "C dec. [ a ] 2 3= ~ $265 (c = 0.525, CHC13). 'H NMR (CDC13): 6 7.60-6.65 (m, 10 a r H), 5.52 (dq, J = 6.9, J = 2.5, CHMeN), 5.28 (s, pz CHI, 4.80 (m, cp HI, 4.36 (m, cp HI, 4.03 (s,5 cp H), 3.70 (m, cp H), 3.21 (st, J = 6.9, 'Pr CHI, 1.92 (d, J = 6.9, CHMeN), 1.11(d, J = 6.9, 3 'Pr CH3), 0.75 (d, J = 6.9, 'Pr CH3). 13C{1H} NMR (CDC13): 6 160-120 (10 ar CH), 103.9 (pz CH), 71.8 (cp CHI, 70.8 (2 cp CHI, 69.4 (6 cp CHI, 50.7 (CHMeN), 21.2 (CHMeN), 27.5 ('Pr CH), 24.8 ('Pr CH), 23.8 ('Pr CH3), 22.7 ('Pr CH3), 21.5 ('Pr CH3), 21.1 (CHMeN), 0.7 ('Pr CH3). 3'P{'H} NMR (CDCl3): 6 -22.9 (s). MS ( m l z ) :548 (M+),396 (M+ - Hpz, loo%), 331 (396 - CP), 212 (396 - PPh2). Anal. Calcd for C33H37FeN2P: C, 72.26; H, 6.80; N, 5.11. Found: C, 72.33; H, 6.58; N, 5.03. 1-{(R)-l-[(S)-2-(Bis(4-fluorophenyl)phosphino)femocenyl]ethyl)-3,5-dimethyl-lHi-pyrazole (3be): from lb (400 mg, 0.83 mmol) and 3,5-dimethyl-lH-pyrazole (2e)(96 mg, 1 mmol, 1.2 equiv), according to the general method. FC (silica, hexane/ethyl acetate 1/1, 1% NEt3): yield 293 mg (67%). Mp: = -308 (C = 0.205, CHC13). 'H NMR (CDC13): 136 "C. 6 7.48-6.66 (m, 8 a r H), 5.57 (dq, J = 6.9, J = 2.5, CHMeN), 5.07 (s, pz CHI, 4.82 (m, cp HI, 4.38 (m,cp HI, 4.06 (s, 5 CPHI, 3.68 (m, cp H), 2.12 (9, pzMe), 1.93 (s, pzMe), 1.78 (d, J = 6.9, CHMeN). 13C{1H} NMR (CDC13): 6 165-120 (8 ar CHI, 104.0 (pz CH), 71.5 (cp CHI, 71.0 (cp CH), 69.9 (5 cp CH), 69.7 (cp CHI, 52.1 (CHMeN), 20.5 (CHMeN), 13.7 (pzMe), 11.3 (pzMe). '9F{'H} NMR (CDC13): 6 -111.87 (d, J = 4, ar F), -114.87 (d, J = 5, ar F). 3IP{lH} NMR (CDCl3): 6 -26.6 (s). MS ( m l z ) : 528 (M+, loo%), 463 (M+ - CP),432 (M+ - Hpz), 367 (482 -

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cp), 311 (367 - Fe). Anal. Calcd for CzsH27FzFeNzP: C, 65.92; H, 5.15; N, 5.30. Found: C, 66.02; H, 5.22; N, 5.30. 1.{ (R)-1-[ (S)-2-(Bis(4-chlorphenyl)phosphino)ferrocenyl]ethyl}-3,5-dimethyl-lH-pyrazole (3ce):from IC (340 mg, 0.67 mmol) and 3,5-dimethyl-lH-pyrazole (2e)(77 mg, 0.8 mmol, 1.2 equiv), according to the general method. FC (silica, hexane/ethyl acetate 2/1, 1% NEt3): yield 222 mg (59%). Mp: = -354 (C = 0.28, CHCl3). 'H NMR (CDC13): 150 "C. [a123~ 6 7.40-6.61 (m, 8 ar H), 5.57 (dq, J = 6.9, J = 2.5, CHMeN), 5.09 (9, pz CH), 4.82 (m, cp H), 4.38 (m, cp HI, 4.07 ( s , 5 cp HI, 3.67 (m, cp H), 2.14 (s, pzMe), 1.94 (s, pzMe), 1.77 (d, J = 6.9, CHMeN). 13C{lH} NMR (CDC13): 6 147-127 (8 a r CH), 104.2 (pz CH), 71.3 (2 cp CHI, 70.9 (cp CH), 69.8 (5 cp CH), 51.9 (CHMeN), 20.3 (CHMeN), 13.6 (pzMe), 11.4 (pzMe). 31P{1H} NMR (CDC13): 6 -26.0 ( 8 ) . MS ( m / ~ )560 : (M+), 464 (M+ Hpz), 398 (464 - cp), 343 (398 - Fe), 121 (Fe-cp, 100%). Anal. Calcd for C2sH2$12FeN2P: C, 62.06; H, 4.85; N, 4.99. Found: C, 61.95; H, 5.08; N, 4.92. 1-{(R)-1-[(S)-2-(Bis(4-methylphenyl)phosphino)femocenyl]ethyl}-3,5-dimethyl-lH-pyrazole (3de):from Id (354 (2e)(109 mg, mg, 0.75 mmol) and 3,5-dimethyl-lH-pyrazole 1.5 mmol, 2 equiv), according to the general method. FC (silica, hexane/ethyl acetate 5/1, 1% NEt3): yield 96 mg (25%). Mp: 156 "C. [ a ] 2 3 = ~ -323 (C = 0.45, CHC13). 'H NMR (CDC13): 6 7.41-6.56 (m, 8 ar H), 5.57 (dq, J = 6.9, J = 2.6, CHMeN), 5.05 (8,pz CH), 4.78 (m, cp H), 4.33 (m, cp H), 4.04 (s, 5 cp H), 3.73 (m, cp H), 2.35 (s, tolMe), 2.21 (s, tolMe), 2.15 (s, pzMe), 1.95 (s, pzMe), 1.80 (d, J = 6.9, CHMeN). 13C{'H} NMR (CDC13): 6 135-128 (8 ar CHI, 104.1 (pz CHI, 94.2 (cp C, 71.7 (cp CH), 70.5 (cp CHI, 69.8 (5 cp CHI, 69.4 (cp CH), 51.8 (CHMeN), 21.4 (8,tome), 21.2 (s, tome), 20.7 (CHMeN), 13.7 (pzMe), 11.3(pzMe). 31P{1H} NMR (CDC13): 6 -24.9 (s). MS ( m l z ) : 520 (M+), 424 (M+ - Hpz, loo%), 359 (424 - CP). Anal. Calcd for C31H33FeN2P: C, 71.55; H, 6.61; N, 5.30. Found: C, 71.54; H, 6.39; N, 5.38. 1-{(R)-1-[(S)-2-(Bis(4-(trifluoromethyl)phenyl)phosphino)ferrocenyl]ethyl}-3-(2-pyridyl)-lH-pyrazole (3ec):from le (200 mg, 0.35 mmol) and 3-(2-pyridine)-lH-pyrazole(2c) (60 mg, 0.42 mmol, 1.2 equiv), according to the general method. FC (silica, hexane/ethyl acetate 3/1, 1% NEt3). yield 140 mg (60%) of a 2:l mixture of the two regioisomers, 3ec and 3ec', respectively. 3ec was isolated in analytically pure form by crystallization fram dichloromethanehexane in 25% yield. Mp: 201 "C dec. [ a I z 3 = ~ -323 (c = 0.76, CHC13). 'H NMR (CDC13): 6 8.51 (m, py H), 7.64-7.50 (m, 5 a r H, pz CHI, 7.08 (m, 2 ar H), 7.01 (m, 2 a r H), 6.79 (m, 2 a r H), 6.31 (d, pz CH, J = 2.3), 5.90 (dq, J = 6.9, J = 3.1, CHMeN), 4.80 (m, cp HI, 4.46 (m, cp HI, 4.10 (s, 5 cp HI, 3.78 (m, cp HI, 1.95 (d, J = 6.9, CHMeN). 13C{1H}NMR (CDCl3): 6 150.2 (ar C, 148.8 (py CH), 135.5 (py CHI, 135.0, 131.6 (2 Ph CH), 127.4 (pz CHI, 124.6, 123.9 (2 Ph CH), 121.5, 119.3 (2 py CHI, 103.8 (pz CH), 93.3 (cp C), 73.9 (cp C), 71.7 (cp CHI, 70.0 (cp CHI, 69.9 (5 CP CHI, 69.7 (cp CHI, 56.1 (CHMeN), 20.8 (CHMeN). 'sF{'H1 NMR (CDCl3): 6 -63.2 (s), -63.3 (s). 31P{1H}NMR (CDC13): 6 -24.6 (s)[3ec'-24.8 (s)]. IR (cm-I): 1607,1594, 1489,1397, 1324,1246,1168,1128,1106,1060,1016,830, 766,698. MS ( m l z ) :677 (M+),658 (M+ - F), 612 (M+ - CP, loo%), 532 (M+ - Hpz), 518, 411, 291, 265 (M+ - Fe-cp - (PhCF&), 145 (Hpz+). Anal. Calcd for C ~ ~ H Z ~ F ~ cF ,~60.29; N ~ PH, : 3.87; N, 6.20. Found: C, 60.31; H, 3.83; N, 6.09. 1-{(R)-l-[(S)-2-(Bis(4-(trifluoromethyl)phenyl)phosphino)ferrocenyl]ethyl}-3,5-dimethyl-lH-pyrazo~e (3ee):from le (300 mg, 0.52 mmol) and 3,5-dimethyl-lH-pyrazole (2e)(60 mg, 0.62 mmol, 1.2 equiv), according to the general method. FC (silica, hexandethyl acetate 1011, 1% NEtd: yield 218 mg (67%). Mp: 112 "C. [ a ] 2 3= ~ -263 (C = 1.0, CHC13). 'H NMR (CDC13): 6 7.64-7.53 (m, 4 Ph H), 7.25 (m, 2 Ph H), 6.84 (m, 2 Ph H), 5.58 (dq, J = 6.9, J = 2.5, CHMeN), 4.99 (s, pz CH), 4.88 (m, cp H), 4.43 (m, cp HI, 4.10 (s, 5 CP H), 3.66 (m, CP HI, 2.15 (s, pzMe), 1.90 (s, pzMe), 1.79 (d, J = 6.9, CHMeN). I3C{'H} NMR (CDC13): 6 146.6, 141.8, 140.0, 136.6 (ar C), 135.0, 131.6 (2 Ph CH), 124.6, 123.9 (2 Ph CH), 104.0 (pz CHI, 93.7

5424 Organometallics, Vol. 14,No. 11, 1995 (cp C), 73.2(cp C), 71.0(CP CHI, 70.9(2 CP CHI, 69.6(5 CP CH), 51.8(CHMeN), 19.9(CHMeN), 13.1(s, pzMe), 10.9 (s, pzMe). l9F{'H} NMR (CDC13): 6 -63.0 ( 8 ) . 31P{1H} NMR (CDC13): 6 -24.0 (s). IR (cm-I): 1607,1555,1396,1323,1163, 1125,1106,1068,1016,829,700. MS ( m l z ) : 628 (M+), 563 (M+ - cp), 532 (M+ - Hpz), 411 (532 - Fe-cp), 216 (Fe(cp)zP, loo%), 96 (Hpz+). Anal. Calcd for C31Hz7F6FeN2P: C, 59.26; H, 4.33;N, 4.46.Found: C, 59.67;H, 4.78;N, 4.24. 1-{(R)-l-[(S)-2-(Bis(4-(trifluoromethyl)phenyl)phosphino)ferrocenyl]ethyl}-5-methyl-3-phenyl-M-pyrazole (3ej): from le (300 mg, 0.52 mmol) and 5-methy1-3-phenyl-lHpyrazole (2j)(100mg, 0.62mmol, 1.2equiv), according to the general method. FC (silica, hexanelethyl acetate 2011, 1% ~ -292 (c = NEt3): yield 210 mg (59%). Mp: 102 "C. [ a 1 2 3= 0.55, CHC13). 'H NMR (CDC13): 6 7.70-7.57(m, 6 Ph H), 7.37-7.22(m, 3 Ph HI, 7.05 (m, 2 Ph HI, 6.83(m, 2 Ph H), 5.71 (dq, J = 6.9,J = 2.7,CHMeN), 5.57(s, pz CHI, 4.94(m, cp HI, 4.47(m, cp HI, 4.15(s, 5 cp H), 3.70(m, cp HI, 2.19(s, pzMe), 1.91(d, J = 6.9,CHMeN). 13C{'H} NMR (CDC13): 6 149.7,142.4,141.6(ar C, 137.7-124.4(ar C, a r CH), 101.9 (pz CH), 93.9(cp C), 73.5(cp C), 71.5(cp CHI, 71.4(cp CH), 69.9(6cp CHI, 52.8(CHMeN), 20.4(CHMeN), 11.4(s, pzMe). '9F{'H} NMR (CDC13): 6 -63.1 (s), -63.2 (s). 31P{1H}NMR (CDC13): 6 -23.6(s). IR (cm-I): 1606,1396,1323,1167,1126, 1106,1060,1016,830, 763,696.MS ( m l z ) : 690 (M+, loo%), 625 (M+ - CP), 532 (M+ - Hpz), 467 (532 - CP), 412 (532 Fe-cp), 373,345,278,217 (M+ - Fe-cp - (PhCF&), 158 (Hpz+). Anal. Calcd for C36H29F6FeN~P:C, 62.63;H, 4.23;N, 4.06. Found: C, 62.83;H, 4.30;N, 3.81. 1-{(R)-1-[ (S)-2-(Bis(4-(trifluoromethyl)phenyl)phosphi-

Burckhardt et al.

heanelethyl acetate 5/1,2% NEt3): yield 321 mg (57%). Mp: 167 "C. [cI]~~D= -324 (C = 0.38,CHC13). 'H NMR (CDC13): 6 7.43-6.51(m, 8 a r H), 5.56(dq, J = 6.9, J = 2.6,CHMeN), 5.07(s,pz CH), 4.78(m, cp Hj, 4.34(m, cp Hj, 4.06(s, 5 cp H), 3.81 (9, OMe), 3.72 (m, cp H), 3.71 (s, OMe), 2.12 (s, pzMe), 1.97 (s, pzMe), 1.79 (d, J = 6.9,CHMeN). 13C{'H} NMR (CDC13): 6 137-113 (8 a r CHI, 104.0(pz CHI, 71.6(cp CHI, 70.5(cp CHI, 69.7(5cp CHI, 69.2(cp CHI, 55.1(9, OMe), 55.0 (s, OMe), 51.7 (CHMeN), 20.5 (CHMeN), 13.7 (pzMe), 11.3 (pzMe). 31P{lH} NMR (CDC13): 6 -27.6 (s). MS ( m l z ) : 552 (M+, loo%), 537 (M+ - Me), 487 (M+ - cp), 456 (M+ - Hpz), 391 (456 - cp), 335 (391 - Fe). Anal. Calcd for C31H33FeN202P C, 67.22;H, 5.90;N, 4.79.Found: C, 67.40;H, 6.02; N, 5.07. 1-{(R)-l-[(S)-2-(Bis(4-methoxyphenyl)phosphino)femcenyl]ethyl}d-methyld-phenyl-1H-pyrazole (3gj):from Ig (275 mg, 0.55mmol) and 5-methyl-3-phenyl-VI-pyrazole (2j)(130 mg, 0.82mmol, 1.5equiv), according to the general method, FC (silica, hexanelethyl acetate 5/1,2%NEt3): yield = -333 (c = 0.27,CHC13). 66 mg (20%). Mp: 112 "C. [aIz3~ 'H NMR (CDC13): 6 7.61-7.15(m, 6 Ph H), 6.99-6.62(m, 5 Ph H), 6.34(m, 2 Ph H), 5.66(dq, J = 6.9, J = 2.8,CHMeN), 5.60(s, pz CHI, 4.83(m, cp H), 4.37(m, cp HI, 4.13(s,5CP HI, 3.81(s, OMe), 3.72(m, cp HI, 3.38(s, OMe), 2.19 (s, pzMe), 1.89 (d, J = 6.9,CHMeN). l3C{IH} NMR (CDC13): 6 160.1, 158.7(Ph-COMe), 149.1,137.5-125.1,113.9(ar C, a r CHI, 113.3,112.9(2Ph CHI, 101.4(pz CHI, 93.0(cp C), 76.6(cp C), 71.2(cp CHI, 70.6(cp CHI, 69.5(5 cp CHI, 68.8(cp CHI, 54.9 (s, OMe), 54.3(s, OMe), 52.1(CHMeN), 20.5(CHMeN), 11.1 (pzMe). 31P{1H}NMR (CDC13): 6 -27.7( 8 ) . IR (cm-'): 1593, no)ferrocenyl]ethyl}-3,5-bis(trifluoromethyl)-lH-pyra- 1497,1462,1440,1284,1246,1176,1095,1030,823,763. MS zole (3ev): from le (300 mg, 0.52 mmol) and 3,5-bis( m l z ) : 614 (M+), 599 (M+ - CH3), 549 (M+ - CP), 456 (M+ (trifluoromethy1)-1H-pyrazole (2v) (204 mg, 1.04 mmol, 2 Hpz, loo%), 391 (456 - cp), 336 (456 - Fe-cp), 158 (Hpz+, equiv), according to the general method. FC (silica, hexanel 100%). Anal. Calcd for C36H35FeN202P: C, 70.36;H, 5.74; ethyl acetate lO/l, 2% NEt3): yield 193 mg (51%). Mp: 73 N, 4.56.Found: C, 70.73;H, 5.91;N, 4.09. "C. [ a ] 2 3 D = -214 (C = 0.45,CHC13). 'H NMR (CDC13): 6 1-{(R)-1-[(S)-2-(Bis(4-methoxyphenyl)phosphino~fer7.65-7.55(m, 4 Ph H), 7.27(m, 2 Ph H), 6.87(m, 2 Ph H), rocenyl]ethyl}-3,5-bis(trifluoromethyl)-lH-pyrazole 6.23(s, pz CH), 5.91 (dq, J = 6.7,J = 3.7,CHMeN), 4.88(m, (3gv): from lg (472mg, 1 mmol) and 3,5-bis(trifluoromethyl)cp HI, 4.51(m, cp HI, 4.16(s, 5 cp H), 3.72(m, cp HI, 1.91(d, lH-pyrazole (2v)(306 mg, 1.5mmol, 1.5equiv), according to J = 6.7,CHMeN). I3C{'H} NMR (CDCl3): 6 141.8,140.2(ar the general method. FC (silica, hexanelethyl acetate 311,2% C), 134.9,131.9(2Ph CHI, 124.7,124.3(2Ph CHI, 104.9(pz NEt3): yield 183 mg (28%). Mp: 93 "C dec. [alZ3~= -200 (c CH), 90.5(cp C), 73.9(cp C), 71.8(cp CHI, 71.5(cp CHI, 70.1 = 0.21,CHC13). 'H NMR (CDC13): 6 7.39-6.52(m, 8 a r H), (cp CH), 69.8( 5 cp CHI, 56.7(CHMeN), 21.1(CHMeN). I9F6.25(s, pz CH), 5.91(dq, J = 6.9, J = 2.8,CHMeN), 4.75(m, {'H} NMR (CDC13): 6 -59.0 (d, PZ CF3, J = 21.51,-62.5 (s, cp H), 4.39(m, cp H), 4.13(s, 5 cp H), 3.81(s, OMe), 3.73(m, pz CF3), -63.2,-63.5(s, 2 PhCF3). 31P{1H} NMR (CDC13): 6 cp H), 3.68(s, OMe), 1.89(d, J = 6.9, CHMeN). 13C{1H}NMR -25.3 (4, J = 21.5).IR (cm-'1: 1608,1561,1396,1324,1270, (CDC13):6 136-113 (8 a r CH), 105.1(pz CH), 72.1 (cp CH), 1208,1169,1129,1107,1061,1017,830,700. MS ( m l z ) : 736 71.3(cp CHI, 70.0(5cp CH), 69.4(cp CHI, 57.0(s, OMe), 55.1 (M+, loo%), 717,615,532 (M+ - Hpz), 412 (532- Fe-cp), 321 (PRz+),234,121 (Fe-cp+). Anal. Calcd for C X H ~ I F ~ Z F ~ N ~ P(s,: OMe), 54.8 (CHMeN), 21.4 (CHMeN). '9F{1H} NMR (CDC13): 6 -58.85 (d, J = 21,PzCF~),-62.18 (s, pzCF3). 31PC, 50.57;H, 2.87;N, 3.80.Found: C, 50.72;H, 3.11;N, 3.62. 1-{(R)-l-[(S)-2-(Bis(4-(dimethylamino)phenyl)phosphi- {'H} NMR (CDC13): 6 -29.1(s). MS ( m l z ) : 660 (M+, loo%), 539 (M+ - Fe-cp), 456 (M+ - Hpz), 391 (456- cp), 336 (456no)ferrocenyl]ethyl}-3,5-dimethyl-M-ppole (3fe): from Fe-cp). Anal. Calcd for C ~ I H ~ ~ F ~ F ~ NC, ZO 56.01; Z P : H, 4.65; If (100mg, 0.19mmol) and 3,5-dimethyl-VI-pyrazole (2e)(70 N, 3.51. Found: C, 56.38; H, 4.12; N, 4.24. mg, 0.73mmol, 3.8equiv), according to the general method. 1-{(R)-l-[ (S)-2-(Bis(3,5-dimethylphenyl)phosphino)ferFC (silica, hexanelethyl acetate loll,2% NEW: yield 55 mg rocenyl]ethyl}-3,5-dimethyl-M-pyrazole (3he): from lh (50%). Mp: 177 "C. = -366 (C = 0.13,CHC13). 'H (497mg, 1 mmol) and 3,5-dimethyl-lH-pyrazole (2e)(306mg, NMR (CDC13): 6 7.38-6.38(m, 8 a r H), 5.56(dq, J = 6.9,J = 3.2mmol, 3.2equiv), according to the general method. FC 2.7,CHMeN), 5.08(s, pz CHI, 4.74(m, cp HI, 4.30(m, cp H), (silica, hexandethyl acetate 5/1,2%NEt3): yield 290mg (53%). 4.08( s , 5 cp H), 3.75(m, cp H), 2.97(s, 2 NMe), 2.84(s,2NMe), 2.05(s, pzMe), 2.00(s, pzMe), 1.82(d, J = 6.9, CHMeN). 13CMp: 182 "C. [a123~ = -289 (C = 0.225,CHC13). 'H NMR J = 2.7, {'H} NMR (CDC13):6 136-112 (8a r CH), 104.0(pz CH), 71.5 (CDC13): 6 7.29-6.35(m, 6 ar H), 5.64(dq, J = 6.9, (cp CH), 70.3 (cp CHI, 69.7(5 cp CH), 68.9(cp CH), 51.6 CHMeN), 5.21 (s,pz CH), 4.82(m, cp H), 4.38(m, cp H), 4.08 (CHMeN), 40.5(s, 2 NMe), 40.5 (s, 2 NMe), 20.8(CHMeN), (s, 5 cp H), 3.81(m, cp H), 2.36(s, 2 PhMe), 2.12(s, pzMe and 12.7(pzMe), 11.5(pzMe). 31P{1H) NMR (CDC13): 6 -28.5(SI. 2 PhMe), 2.03 (s, pzMe), 1.87 (d, J = 6.9,CHMeN). 13C{'H} MS ( m l z ) : 578 (M+, loo%), 513 (M+ - CP), 482 (M+ - Hpz), NMR (CDC13): 6 133-129 (6a r CH), 104.0(pz CHI, 71.6(cp 417 (482 - cp), 362 (417 - Fe). Anal. Calcd for C33H39CH), 70.4(cp CH), 69.7(5 cp CHI, 69.3(cp CHI, 51.8(CHMeN), FeN4P: C, 68.51;H, 6.79;N, 9.68. Found: C, 68.11;H, 7.13; 21.3 (CHMeN and 2 PhMe), 13.7(pzMe and 2 PhMe), 11.3 N, 9.48. (pzMe). 31P{'H} NMR (CDC13): 6 -23.9 (s). MS ( m l z ) : 548 1-{(R)-l-[(S)-2-(Bis(4-methoxyphenyl)phosphino)ferro- (M+, loo%), 483 (M+ - CP), 452 (M+ - Hpz), 387 (452 - CP), cenyl]ethyl}-3,5-dimethyl-lH-pyrazole (3ge): from lg (472 332 (387- Fe), 226 (332- xyl), 121 (Fe-cp), 96 (Hpz'). Anal. mg, 1 mmol) and 3,5-dimethyl-lH-pyrazole (2e)(144mg, 1.5 N, 5.11.Found: C, Calcd for C33H37FeNzP: C, 72.26;H, 6.80; mmol, 1.5equiv), according to the general method. FC (silica, 72.35;H, 6.95;N, 5.05.

Pyrazole-Containing Ferrocenyl Ligands

Organometallics, Vol. 14,No. 21, 1995 5425

1-{(R)-1-[(~)-2-(Bis(3,5-bis(trinuoro"thyl)phenyl~phos- Anal. Calcd for C30H39FeN2P: C, 70.04; H, 7.64; N, 5.45. phino)ferrocenyl]ethyl}-3,S-dimethyl-1H-pyrazole Found: C, 70.05; H, 7.74; N, 5.27. 1-{(R)-1-[ (S)-2-(Dicyclohexylphosphino)ferrocenyll(3ie): from li (100 mg, 0.14 mmol) and 3,5-dimethyl-1Hethyl}-3,5-dimethyl-lH-pyrazole (3ke): from lk (1.13 g, 2.5 pyrazole (2e)(27 mg, 0.28 mmol, 2 equiv), according to the mmol) and 3,5-dimethyl-LH-pyrazole (2e)(365 mg, 3.75 mmol, general method. FC (silica, hexanelethyl acetate loll, 2% 1.5equiv), according to the general method. FC (silica, hexand ~ -251 (c = NEt3): yield 67 mg (63%). Mp: 122 "C. [ a l Z 3= ethyl acetate lO/l, 2% NEt3): yield 588 mg (45%). Mp: 100 0.28, CHC13). lH NMR (CDC13): 6 7.85-7.21 (m, 6 ar H), 5.65 = -128 ( c = 0.405, CHC13). IH NMR (CDC13): 6 "C. [a]23~ (dq,J=6.9,J=2.7,CHMeN),5.00(s,pzCH),4.84(m,cpH), 5.67 (s, pz CH), 5.51 (dq, J = 6.9, J = 2.6, CHMeN), 4.66 (m, 4.45 (m, cp HI, 4.07 (s, 5 cp HI, 3.56 (m, cp HI, 2.05 (s, pzMe), cp H), 4.38 (m, cp H), 4.14 (s, 5 cp H), 4.11 (m, cp H), 2.35 (s, 1.72 (d, J = 6.9, CHMeN), 1.67 ( 6 , pzMe). 13C{lH) NMR pzMe), 2.11 (s, pzMe), 1.75 (d, J = 6.9, CHMeN), 1.6-0.5 (m, (CDC13): 6 147-125 (6 a r CH), 105.1 (pz CH), 71.6 (cp CH), 10 Cy CH2 and 2 Cy CH). 13C{IH} NMR (CDC13): 6 104.9 (pz 71.4 (cp CH), 70.1 (6 cp CHI, 53.6 (CHMeN), 19.5 (CHMeN), CH), 70.2 (cp CH), 70.0 (5 cp CH), 69.8 (cp CH), 68.8 (cp CHI, 12.9 (pzMe), 11.5 (pzMe). 19F{lH) NMR (CDC13): 6 -63.3 (s, 52.1 (CHMeN), 33.4-26.5 (10 Cy CHZ and 2 Cy CHI, 21.5 4 ar CF3). 3IP{IH} NMR (CDC13): 6 -23.4 (9). MS ( m l z ) : 764 (CHMeN), 13.9 (pzMe), 11.7 (pzMe). 31P{1H}NMR (CDC13): 6 (M+, loo%), 643 (M+ - Fe-cp), 216 (Ph with 2 CF3), 121 (Fe: (M+), 421 (M+ - Cy), 326 (421 -16.1 ( 6 ) . MS ( m l . ~ )504 cp). Anal. Calcd for C33H26F1~FeN~P: C, 51.86; H, 3.30; N, Hpz), 243 (326 - Cy, 100%). Anal. Calcd for C29H41FeNzP: 3.66. Found: C, 51.59; H, 3.54; N, 3.64. 1-{(R)-l-[(S)-2-(Dibutylphosphino)ferrocenyllethyl}- C, 69.05; H, 8.19; N, 5.55. Found: C, 68.24; H, 8.20; N, 5.44. X-ray Crystallographic Studies of 3af, 3ah, 34, 3aq', 3,5-dimethyl-lH-pyrazole (3je): from lj (401 mg, 1 mmol) 3as,and 3ec. Data were measured with variable scan speeds (2e)(192 mg, 2 mmol, 2 equiv), and 3,5-dimethyl-lH-pyrazole to ensure constant statistical precision on the collected intensiaccording to the general method. FC (silica, hexanelethyl ties. One standard reflection was measured every 120 reflecacetate 4/1, 2% NEt3): yield 117 mg (26%, red oil). [ a l Z 3=~ tions; no significant variation was detected. -249 (C = 0.145, CHC13). 'H NMR (CDC13): 6 5.65 (s,PZ CHI, The structures were solved either by direct (3ah,34,3aq', 5.58 (dq, J = 6.9, J = 2.8, CHMeN), 4.67 (m, cp H), 4.32 (m, and 3as)or Patterson (3afand 3ec)methods and refined by cp HI, 4.13 (s, 5 cp H), 3.42 (m, cp HI, 2.32 (s, pzMe), 2.08 (s, full-matrix least squares using anisotropic displacement papzMe), 1.75 (d, J = 6.9, CHMeN), 1.72-0.6 (m, 6 Bu CHZand rameters for all non-hydrogen atoms. The contributions of the 2 BU CH3). 13C{lH} NMR (CDCl3): 6 104.7 (PZ CH), 69.9 (CP hydrogen atoms in their idealized positions (Riding model with CH),69.8 (5 cp CH),69.3 (cp CH),68.6 (cpCH),52.5 (CHMeN), fixed isotropic U = 0.080 Az)were taken into account but not 29.5-24.3 (6 Bu CH2), 20.4 (CHMeN), 13.9 (pzMe), 13.8 (2 Bu refined. All calculations were carried out by using the Siemens CH3), 11.6 (pzMe). 31P{1H} NMR (CDC13): 6 -42.3 (5). MS SHELXTL PLUS system. ( m / z ) :452 (M+),395 (M+ - Bu, loo%), 299 (395 - Hpz), 243 (299 - Bu), 121 (Fe-cp), 95 (Hpz+), 56 (Fe). Anal. Calcd for Acknowledgment. This research was in part supC25H3,FeN2P: C, 66.37; H, 8.24; N, 6.19. Found: C, 67.10; H, ported by LONZA Ltd. (Ph.D. grant to U.B.). We are 7.83; N, 5.85. 1-{(R)-l-[(S)-2-(Dibutylphosphino)ferrocenyllethyl}-5- grateful to V. Gramlich for his valuable help with the methyl-3-phenyl-lH-pyrazole(3$: from lj (300 mg, 0.75 X-ray structural analyses. mmol) and 5-methyl-3-phenyl-lH-pyrazole (2j) (142 mg, 0.90 mmol, 1.2 equiv), according to the general method. FC (silica, Supporting Information Available: Tables of crystal hexaneldiethyl ether lO/l): yield 54 mg (14%, orange oil). [ a I z 3 ~ data and refinement details, atomic coordinates, all bond = -225 (C = 0.14, CHC13). IH NMR (CDC13): 6 7.67 (m, 2 Ph distances and angles, anisotropic displacement coefficients for H), 7.33-7.20 (m, 3 P h HI, 6.21 (s, pz CHI, 5.74 (dq, J = 6.9, non-carbon atoms, and coordinates of hydrogen atoms for 3af, J = 2.8, CHMeN), 4.71 (m, cp H), 4.36 (m, cp H), 4.18 (s, 5 cp 3ah,3 4 , 3aq', 3as, and 3ec, ORTEP views of molecules A HI, 4.09 (m, cp HI, 2.39 (s, pzMe), 1.86 (d, J = 6.9, CHMeN), and B as well as of all three independent molecules in the unit 1.82-0.5 (m, 6 Bu CH2 and 2 Bu CH3). 13C{IH} NMR cell for 3aq' (Figures Sl-S3),and ORTEP views of 3af,3ah, (CDC13): 6 149.2, 137.8, 134.0 (ar C, 127.9, 126.6, 125.2 (Ph 3 4 , 3as, and 3ec (Figures S4-S8) (78 pages). Ordering CHI, 102.2 (pz CHI, 92.5 (cp C), 78.2 (cp C), 69.8 (cp CHI, 69.3 information is given on any current masthead page. Tables (5 cp CHI, 69.1 (cp CH), 68.2 (cp CHI, 53.1 (CHMeN), 29.5of calculated and observed structure factors for all six com23.9 (6 Bu CH2), 20.2 (CHMeN), 13.7 (Bu CH3), 13.3 (Bu CH3), pounds (55 pages) may be obtained from the authors upon 11.5(pzMe). 31P{lH} NMR (CDC13): 6 -42.3 (s). MS ( m l z ) : request. 514 (M+),457 (M+ - Bu), 372,356 (M+ - Hpz), 327,300 (356 OM950475C - Bu), 272, 258, 243, 212, 158 (Hpz+, loo%), 121 (Fe-cp+).