New ferrocenyl thio- and selenoether ligands. Preparation

Organometallics , 1986, 5 (3), pp 482–490. DOI: 10.1021/om00134a015. Publication Date: March 1986. ACS Legacy Archive. Cite this:Organometallics 5, ...
0 downloads 0 Views 1MB Size
Download PDF
482

Organometallics 1986,5, 482-490

New Ferrocenyl Thio- and Selenoether Ligands. Preparation, Characterization, and Their Palladium( I I ) Complexes as Catalysts for Selective Hydrogenation and Grignard Cross-Coupling Robert V. Honeychuck, Michael 0. Okoroafor, Lie-Hang Shen, and Carl H. Brubaker, Jr.' Depatfment of Chemistry, Mlchigan State University, East Lansing, Michigan 48824 Received July 7, 1985

A number of previously unknown ferrocenyl thioethers and selenoethers, (q5-C5H5)Fe(q5-C5H3-1CH2NMe2-2-SR)(R = Me, Et, i-Pr, i-Bu, isopentyl, and Ph), (R,S)-(s5-C5Hs)Fe(s5-C5H3-1-CH(CH3)NMe2-2-SR) (R = Me, Et, LPr, Ph, and CHzPh),(q5-C5H5)Fe(q5-C5H3-1-CH NMe2-2-SeR)(R = Me, Ph, and 4-chlorophenyl), (S,R)-(115-C5H5)Fe(q5-CSH3-1-CH(CH3)NMe2-2-SePh), (75-C5H4SeR)zFe(R = Me and Ph), and (v5-C5H6)Fe(05-C5H4SeMe), have been made from the appropriate ferrocene precursors via lithiation and reaction with RSSR or RSeSeR. The following techniques were used for characterization: 'H and 13CNMR, IR, MS, and elemental analysis. The PdClz complex of (q5-C5H5)Fe(s5-C5H3-l-CHzNMez-2-S-i-Pr) is a selective hydrogenation catalyst under homogeneous and hetero eneous conditions for the reduction of dienes to monoenes. The PdClz complexes of (R,S)-(s5-C5H5)Fe(q f-C5H3-1-CH(CH3)NMez-2-SPh)and (S,R)-(q5-C5H5)Fe(q5-C5H3-1-CH(CH3)NMez-2-SePh) are effective Grignard cross-coupling agents coupling 1-chloro-1-phenylethane with allylmagnesium bromide and all lmagnesium chloride in high yield. The P ~(7) ! ~-C5H5)Fe(s5.-C5H3-1-CHzNMez-2-SeR) F~ (R preparation of the PdClz complexes of ( T ~ - C ~ H , S ~and = Me and 4-chlorophenyl)is also described. This paper presents the fmt transition-metal-catalyzedGrignard cross-coupling reaction that used a ferrocenyl thioether or selenoether as a ligand.

Introduction Since the first appearance of [ (dimethylamino)methyllferrocene ( l ) , I [ 1-(dimethylamino)ethyl]ferrocene (4),2 ferrocene (7),3and bromoferrocene (to),'' much effort has been expended on the reactions of their lithiation products 2,5, 8, and 11. For example, electrophiles have been used to give 3 (R = PPh2,5 SiMe3,6 2-pyridy1,' C(OH)Ph2,sCl,9 and B(OH)2.10 Various stereoisomers of 6 have been known for y e a r ~ . l l ?Their ~ ~ ~ popularity as chiral ligands in catalysis stems from the ready resolution (1) Hauser, C. R.; Lindsay, J. K. J. Org. Chem. 1956, 21, 382-383. (2) Hauser, C. R.; Lindsay, J. K. J . Org. Chem. 1957, 22, 906-908. (3) Kealy, T. J.; Pauson, P. L. Nature (London)1951,168,1039-1040. (4) Nesmeyanov, A. N.; Perevalova, E. G.; Nesmeyanova, 0. A. Dokl. Akad. Nauk SSSR 1975,84, 255-267. (5) Kotz, J. C.; Nivert, C. L.; Lieber, J. M.; Reed, R. C. J . Organomet. Chem. 1975, 84, 255-257. (6) Marr, G. J . Organomet. Chem. 1967,9, 147-152. (7) Booth, D. J.; Rockett, B. W. Inorg. Nucl. Chem. Lett. 1970, 6 , 121-124. (8) Slocum, D. W.; Rockett, B. W.; Hauser, C. R. Chem. Ind. (London) 1964, 1831-1832. (9) Gay, R. L.; Crimmins, T. F.; Hauser, C. R. Chem. Ind. (London) 1966, 1635. (10) Booth, D. J.; Marr, G.; Rockett, B. W.; Rushworth, A. J. Chem. SOC.C 1969, 2701-2703. (11) Hayashi, T.; Yamamoto, K.; Kumada, M. Tetrahedron Lett. 1974, 4405-4408. Hayashi, T.; Tajika, M.; Tamao, K.; Kumada, M. J . Am. 1976,98,3718-3719. Hayashi,T.; Kumada, M. Fundam. Res. Chem. SOC. Homogeneous Catal. 1978,2,159-180. Hayashi, T.; Mise, T.; Fukushima, M.; Kagotani, M.; Nagashima, N.; Hamada, Y.; Matasumoto, A,; Kawakami, S.; Konishi, M.; Yamamoto, K.; Kumada, M. Bull. Chem. SOC. Jpn. 1980,53,1138-1151. Cullen, W. R.; Yeh, E.-S. J. Organomet. Chem. 1977, 139, C13-Cl6. Cullen, W. R.; Einstein, F. W. B.; Huang, C.-H.; Willis, A. C.; Yeh, E.-S. J . Am. Chem. SOC. 1980, 102,988-993. Cullen, W. R.; Woollins, J. D. Coord. Chem. Rev. 1981,39, 1-30. Cullen, W. R.; Woollins, J. D. Can. J. Chem. 1982,60, 1793-1799. Butler, 1. R.; Cullen, W. R.; Reglinski, J.; Rettig, S. J. J.Organomet. Chem. 1983,249, 183-194. Marquarding, D.; Klusacek, H.; Gokel, G.; Hoffmann, P.; Ugi, I. J. Am. Chem. SOC.1970,92,5389-5393. Gokel, G.; Hoffmann, P.; Klusacek, H.; Ugi, I. Angew. Chem., Int. Ed. Engl. 1970, 9, 64435. Valkovich, P. B.; Gokel, G. W.; Ugi, I. K. Tetrahedron Lett. 1973, 2947-2950. Battelle, L. F.; Bau, R.; Gokel, G. W.; Oyakawa, R. T.; Ugi, I. K. J. Am. Chem. SOC. 1973,95,482-486. Stuber, S.; Ugi, I. Synthesis 1973,309. Knowles, W. S. Acc. Chem. Res. 1983, 26, 106-112. Yamamoto, K.; Wakatsuki, J.; Sugimoto, R. Bull. Chem. SOC.Jpn. 1980,53, 1132-1137.

0276-7333/86/2305-0482$01.50/0

of 4 into its R and S enantiomers.12 Among the many compounds 9 derived from 1,l'-dilithioferrocene (8) are those where the electrophilic atom comes from the transition metals (9, R = AuPPh313 and Cu14),the actinides (9, R = UCp315),group IVA (1461)(9, R = organic groups16 and silyl groups17), and group VA (1561)(9, R = AsMez, AsPh2, PMez, PPh2,18and P ( ~ - B U ) ~Ferrocenyllithium ~~). (1l), upon reaction with appropriate electrophiles, gives 12 (R = C02H, SiPh3, &Me3, CPh20H,20D, and C1).21 Group VIA (1661) atoms were not used as electrophiles with 2,5,8, and 11 until recently when it was found in this l a b o r a t ~ r y that ~ ~ - 8~ and ~ 11 react with alkyl disulfides, phenyl disulfide, and thiuram disulfides. As an extension (12) Gokel, G. W.; Ugi, I. K. J . Chem. Educ. 1972, 49, 294-296. (13) Perevalova, E. G.; Lemnovskii, D. A.; Afanasova, 0. B.; Dyadchenko, V. P.; Grandberg, K. I.; Nesmeyanov, A. N. Izu. Akad. Nauk. SSSR, Ser. Khim. 1972,21, 2594-2596. (14) Sedova, N. N.; Moiseev, S. K.; Sazonova, V. A. J . Organomet. Chem. 1982,224, C53-C56. (15) Tsutsui, M.; Ely, M. J. Am. Chem. SOC. 1974, 96, 3650-3651. (16) Nesmeyanov, A. N.; Perevalova, E. G.; Golovnya, R. V.; Nesmeyanova, 0. A. Dokl. Akad. Nauk SSSR 1954,97,459-461. Okuhara, K. J. Org. Chem. 1976, 41, 1487-1494. Sosin, S. L.; Alekseeva, V. P.; Litvinova, M. D.; Korshak, V. V.; Zhigach, A. F. Vysokomol.Soedin., Ser. E 1976, 18, 703-707. Hanlan, A. J. L.; Ugolick, R. C.; Fulcher, J. G.; Togashi, S.; Bocarsly, A. B.; Gladysz, J. A. Inorg. Chem. 1980, 19, 1543-1551. Cassens, A.; Eilbracht, P.; Mueller-Westerhoff, U. T.; Nazzal, A.; Neuenschwander, M.; Prossdorf, W. J. Organomet. Chem. 1981,205, C17-CZO. (17) Goldberg, S. I.; Mayo, D. W.; Vogel, M.; Rosenberg, H.; Rausch, M. J. Org. Chern. 1959,24,824-826. Rausch, M.; Vogel, M.; Rosenberg, H. J. Org. Chern. 1957,22,900-903. Wrighton, M. S.; Palazzotto, M. C.; Bocarsly, A. B.; Bolts, J. M.; Fischer, A. B.; Nadjo, L. J. Am. Chem. SOC. 1978,100, 7264-7271. (18) Bishop, J. J.; Davison, A.; Katcher, M. L.; Lichtenberg, D. W.; Merrill, R. E.;Smart, J. C. J. Organomet. Chem. 1971, 27, 241-249. (19) Cullen, W. R.; Kim, T.-J.; Einstein, F. W. B.; Jones, T. Organometallics 1983, 2, 714-719. (20) Seyferth, D.; Hofmann, H. P.; Burton, R.; Helling, J. F. Inorg. Chern. 1962,1, 287-231. (21) Hedberg, F. L.; Rosenberg, H. Tetrahedron Lett. 1969,4011-4012. (22) McCulloch, B.; Ward, D. L.; Woollins, J. D.; Brubaker, C. H., Jr. Organometallics 1985, 4, 1425-1432. (23) McCulloch, B.; Brubaker, C. H., Jr. Organometallics 1984, 3, 1707-1711. (24) McCulloch, B. Ph.D. Thesis, Michigan State University, 1983.

0 1986 American Chemical Society

qLlMe2

Organometallics, Vol. 5, No. 3, 1986 483

New Ferrocenyl Thio- a n d Selenoether Ligands eIeclrophile_

q N M e 2

N Me2

3

2

1

LI n-BuLi

( S )-4

@

declrophile

(5'.R ) - 6

(S.S)-5 n-BuLi

TMEDA

a:

7

e l e c t rophile

-

GBr n-BuLi E120

10

-

olectrophile

11

12

of this work, it has now been discovered that 2 , 5 , 8 , and 11 react with various disulfides and diselenides, yielding new ferrocenyl thioethers and selenoethers. The preparation and characterization of these compounds and some of their PdClz complexes are presented in this paper. The successful use of some of the PdClz complexes in selective hydrogenation and Grignard cross-coupling is also described.

Experimental Section Proton and 13CNMR spectra were obtained by use of a Bruker WM 250 spectrometer in chloroform-d with Me4Si as internal standard. Infrared spectra were recorded by use of a Perkin-Elmer 457 machine. Mass spectra were obtained by means of a Finnigan 4021 instrument with INCOS data system. Elemental analyses were performed by Spang Microanalytical Laboratory, Eagle Harbor, MI, and Galbraith Laboratories, Knoxville, TN. Gas chromatography was carried out by using a Hewlett-Packard 5880A instrument. [(Dimethy1amino)methyllferrocene was made by the standard methodz5or was purchased. Amine 4 was made and resolved as previously described.12 Solvents were dried and distilled by standard methods.26 The (1,3-cyclooctadiene + cyc1ooctene):cyclooctane ratios in the hydrogenations were determined by gas chromatography. The 1,3-cyclooctadiene:cyclooctene ratios were determined by integration of the olefinic region of the 'H NMR spectra. 1-[(Dimet hylamino)methyl]-2-(met hylse1eno)ferrocene (13, R = Me). A 2.7 M solution of n-BuLi in hexane (4.1 mL, 11 mmol) was added over a half-hour period t o a solution of [(dimethylamino)methy1]ferrocene (1,2.7 g, 11mmol) in 150 mL of dry ether under argon in a 250-mL round-bottomed Schlenk flask equipped with a magnetic stirring bar. The suspension was stirred for 3 h at room temperature, and then a solution of methyl diselenide (2.07 g, 11.0 mmol) in 20 mL of ether was added dropwise over a 30-min period a t -78 "C. The reaction mixture was further stirred for 30 h. The mixture was filtered, and the filtrate was slowly added to aqueous NaHC03 carbonate with cooling in an ice bath. The resulting organic layer and ether extracts from the aqueous layer were combined, washed with ice water, dried over anhydrous MgS04, and concentrated in vacuo to afford a brown oil, which was chromatographed on a silica gel column by gradient elution (hexane/benzene/ether). The product was obtained as brown-yellow plates: yield 80%; mp 75-76 "C; IR (Nujol) 460,495,510, 528,820,1002,1022,1110, 1180,1208, 1305 cm-'; MS, m / e (relative intensity) 44 (44, NMe2), 56 (93, Fe), 58 (75, CHzNMe2),65 (113, C5H5),95 (11,SeMe), 121 (100, C5H5Fe),242 (30, M+ - SeMe), 279 (3, Mf - CH2NMe2),293 (7, Lednicer, D.; Hauser, C. R. Org. Synth. 1973,5, 434-436. Gorgon, A. J.; Ford, P. A. 'The Chemist's Companion"; Wiley: New York, 1972; pp 445-447. (25) (26)

1-[(Dimethylamino)methyl]-2-(phenylseleno)ferrocene (13, R = P h ) . A 2.7 M solution of n-BuLi in hexane (4.1 mL, 11 mmol) was added over a half-hour period to a solution of [(dimethylamino)methyl]ferrocene (1,2.7 g, 11 mmol) in 100 mL of dry ether under nitrogen in a 250-mL round-bottomed Schlenk flask equipped with a magnetic stirring bar. The suspension was stirred for 3 h a t room temperature under nitrogen, and then a solution of phenyl diselenide (3.43 g, 11.0 mmol) in 20 mL of ether was added dropwise over a 30-min period at -78 "C. The reaction mixture was further stirred for 12 h. The mixture was filtered, and the filtrate was washed four times with 10-mL portions of ice-cold distilled H,O. The organic layer was evaporated to a brown-yellow oil, which was chromatographed on a silica gel column by gradient elution (hexane/benzene). The product was obtained as a brown-yellow solid: yield 65%; mp 42-44 "C; IR (Nujol, CsI) 690,735,820,1000,1025,1108, 1180,1264,1583cm-'; MS, m / e (relative intensity) 399 (45, M'). Anal. Calcd for ClSHZ1FeNSe: C, 57.32; H, 5.32. Found: C, 57.63; H, 5.13. 1-[(Dimethylamino)methyl]-2-[ (4-~hlorophenyl)seleno]ferrocene (13, R = 4-Chlorophenyl). A 2.7 M solution of n-BuLi in hexane (2.4 mL, 6.4 mmol) was added over a half-hour period to a solution of [(dimethylamino)methyl]ferrocene (1,1.2 mL, 5.8 mmol) in 80 mL of dry ether under argon in a 250-mL roundbottomed Schlenk flask equipped with a magnetic stirring bar. The suspension was stirred for 3 h at room temperature, and then a solution of bis(4-chlorophenyl) diselenide (2.02 g, 5.30 mmol) in 100 mL of dry ether was added dropwise over a 30-min period a t -78 "C. The reaction mixture was then stirred for 30 h. After 4 h of heating under reflux, 50 mL of aqueous NaHC03 was slowly added and cooled in an ice bath. The resulting organic layer and ether extracts from the aqueous layer were combined, washed with ice water, dried over anhydrous Na2S04,and concentrated in vacuo t o afford an orange-brown oil. The oil was chromatographed on a silica gel column by gradient elution (hexane/benzene/ether). The product was obtained as a dark brown oil, which solidified on cooling: yield 63%; IR (neat) 460, 493, 530, 810, 825, 1012, 1090,1110,1180,1240,1264,1364,1358,1478,1570,1667-2000, 2770,2820, 2860, 2950, 2980, 3050-3100 cm-'; MS, m / e (relative intensity) 44 (8, NMe,), 56 (37, Fe), 58 (57, CH,NMe,), 65 (7, C5H5), 121 (79, C5H5Fe), 191 (4, SeC6H4C1), 242 (100, M+ SeC&4C1), 389 (11, M+ - NMe2),433 (39, M'). Anal. Calcd for Cl9HzoC1FeNSe: C, 52.75; H, 4.66. Found: C, 52.85; H, 4.71. 1-[(Dimethylamino)methyl]-2-ferrocenyl Thioethers (14). Thioether derivatives 14 were prepared by lithiation of [(dimethylamino)methyl]ferrocene (1)in diethyl ether with 1.1equiv of n-BuLi (1.6 M in hexane) under N2 in Schlenk flasks with rubber septa. After 12 h, 1.0 equiv of alkyl disulfide (neat) or phenyl disulfide (in 250 mL of Et,O) was added via cannula at 25 OC. Because of the exothermic nature of the reaction with the disulfides, it is advisable to cool large scale preparations to 0 "C. Four hours later, 100-200 mL of H 2 0 was added, the mixture in each case was filtered, and the organic layer was separated and dried (Na2S04). Solvents were removed on the rotary evaporator. The alkyl derivatives were purified on silica gel columns by using CH,Cl,/MeOH. An analytical sample of 14, R = Ph, was obtained by repeated column chromatography with benzene/ethyl ether. The yield reported in the latter case is the yield of the analytical sample. 1-[(Dimethylamino)methyl]-2-(methylthio)ferrocene (14, R = Me). [(Dimethylamino)methyl]ferrocene (9.2 mL, 0.046 mol) gave 2.27 g (17%) of the product as a yellow solid: mp 77-78 "C; IR (Nujol, CsI) 719, 805, 888, 946, 996, 1102 cm-l; MS, m / e (relative intensity) 44 (10, NMe,), 47 (1,SMe), 56 (15,Fe), 58 (15, CHzNMez), 65 (2, C5H5), 121 (41, C5H5Fe), 231 (2, M+ CH2NMe2),242 (44,M'- SMe),245 ( 3 7 , M + - NMe,), 289 (89, M'). Anal. Calcd for Cl,H19FeNS: C, 58.14; H, 6.62. Found: C, 58.08; H, 6.81. 1-[(Dimethylamino)methyl]-2-(ethylthio)ferrocene(14, R = Et). [(Dimethylamino)methyl]ferrocene(8.1 mL, 09.041 mol) gave 5.60 g (45%) of brown oil: IR (Nujol, CsI) 720,808, 888,946, 998, 1103, 1178, 1264 cm-'; MS, m / e (relative intensity) 44 (23, NMe,), 56 (61, Fe), 58 (76, CH2NMe2),65 (21, C5H5),121, (100, FeCp), 242 (41, M+ - SEt), 259 (20, M+ - NMe,), 274 (4, M+ Et), 303 (61, M'). Anal. Calcd for Cl5HZlFeNS: C, 59.41; H, 6.98;

a: 9

8

M+ - NMe,), 337 (13, M'). Anal. Calcd for C14HlgFeNSe: C, 50.64; H, 5.70. Found: C, 49.95; H, 5.79.

484

Organometallics, Vol. 5, No. 3, 1986

S, 10.57. Found: C, 59.61; H, 7.15; S, 10.48. 1-[ (Dimethylamino)methy1]-2-(isopropylthio)ferrocene (14, R = i-Pr). [(Dimethylamino)methyl]ferrocene(6.3 mL, 0.082

mol) gave 8.22 g (32%) of brown crystals: mp 82-83 "C; IR (Nujol, KBr) 662,815,891,998, 1018,1103,1180, 1260,3095 cm-'; MS, m / e (relative intensity) 43 (32, i-Pr), 44 (8, NMe,), 56 (26, Fe), 58 (28, CH,NMe2), 65 (4, C5H5), 121 (52, C5HjFe), 196 (9, M+ C5H,Fe), 242, (48, M+ - S-i-Pr),259 (3, M+ - CH,NMe,), 273 (23, M+ - NMe,), 274 (24, M+ - i-Pr), 302 (3, M+ - CH,), 317 (100, M+). Anal. Calcd for ClGHz3FeNS: C, 60.57; H , 7.31; S, 10.10. Found: C, 60.54; H, 7.40; S, 10.16. 1-[ (Dimethylamino)methyl]-2-(isobutylthio)ferrocene ( 14, R = i-Bu). [(Dimethylamino)methyl]ferrocene(16.3 mL, 0.0823

mol) gave 12.0 g (43.9%) of brown oil: IR (Nujol, CsI) 718, 808, 888,945,993,1103cm-I; MS, m / e (relative intensity) 43 (8, LPr), 44 (11, NMe,), 56 (45, Fe), 58 (48, CH,NMe), 65 (6, CjHj), 121 (100, M+). Anal. Calcd for CI7Hz5FeNS:C, 61.63; H, 7.61; S, 9.68. Found: C, 61.17; H, 7.69; S, 9.82. 1-[ (Dimethylamino)methy1]-2-(isopentylthio)ferrocene (14, R = Isopentyl). [(Dimethylamino)methyl]ferrocene(18.4

mL, 0.0930 mol) gave 10.2 g (31.7%) of brown oil: IR (Nujol, CsI) 720, 810, 888, 947,995, 1103 cm-I; MS, m / e (relative intensity) 56 (17, Fe), 53 (19, CH,NMe2), 65 (3, C5H5),121 (20, FeCp), 153 (3, M+ - FeCp-isopentyl), 242 (15, M+ - S-isopentyl), 274 (2, Mt - NMe,), 345 (20, M+). Anal. Calcd for CI8Hz7FeNS:C, 62.61; H, 7.88; S, 9.28. Found: C, 62.82; H, 8.07; S, 9.42. 1-[(Dimethylamino)methyl]-2(pheny1thio)ferrocene ( 14, R = P h ) . [(Dimethylamino)methyl]ferrocene(16.3 mL, 0.0823 mol) gave 0.030 g (0.10%) of a yellow solid mp 6 H 8 "C; IR (neat) 690,740,820,1000,1025,1104,1176,1260,1375,1480,1580,2760, 2810, 2940, 3050-3100 cm-'; MS, m / e (relative intensity) 56 (43, Fe), 58 (32, CH,NMe2), 121 (78, C,H5Fe), 242 (94, M+ - SPh), 351 (92, M+). Anal. Calcd for ClSHz1FeNS: C, 64.96: H , 6.03; S, 9.13. Found: C, 65.27; H, 5.87; S, 9.14. (S )-I-[ (Dimethy1amino)et hyllferrocene [ (S)-4)].Amine 4 was prepared and resolved by using (+)-tartaric acid as described by Gokel and Ugi.', The amine was recrystallized twice to give a dark brown oil that partly solidified on cooling: 'H NMR 6 1.44 (d, 3 H, CHJ, 2.09 (s, 6 H, NMe,), 3.60 (q, 1 H, CH), 4.11 (s, 5 H, C5Hj), 4.12 (m, 4 H, C5H4);[a]DZ5 -14.0" (lit." [(u]DZ5 -14.1'). The R isomer was isolated similarly.'2 ( R ,S )-1-[l-(Dimethylamino)ethyl]-2-(methylthio)ferrocene (15, R = Me). Amine (R)-4 (1.5 g, 5.8 mmol) was dissolved in 50 mL of dry ether and placed in a 100-mL roundbottomed flask equipped with a side arm. The solution was cooled to -78 "C, and 4.0 mL (6.4 mmol) of n-BuLi was added slowly via syringe. The orange suspension was allowed to reach room temperature and stirred overnight. Methyl disulfide (0.53 mL, 5.9 mmol) was added dropwise via syringe at -78 "C. The solution was allowed to reach room temperature and stirred for 12 h, after which 20 mL of H 2 0 was added. The organic layer was separated, dried, and evaporated to give a dark oily residue. The oil was separated on alumina, with hexane/CH,Cl, to give the product which upon recrystallization from hexane/petroleum ether gave yellow crystals: yield 45%; mp 64-66 "C; MS, m / e (relative intensity) 303 (19, M+). Anal. Calcd for C16H2,FeNS: C, 59.41; H, 6.93. Found: C, 59.54; H, 6.89. (R,S)-I-[ l-(Dimethylamino)ethyl]-2-(ethylthio)ferrocene (15, R = Et). The procedure was the same as for 15, R = Me, except that 0.73 mL (5.9 mmol) of Et& was used: yield 45%; MS, m / e (relative intensity) 40 (loo), 56 (17, Fe), 7 2 (9, CH(CH3)NMe2),121 (29, FeCp), 272 (44, M+ - "Me2), 302 (23, M+ - CHJ, 317 (53, M'). ( R,S )-1-[ l-(Dimethylamino)ethyl]-2-(isopropylthio)ferrocene (15, R = i-Pr). The procedure was the same as for 15, R = Me, except that 0.94 mL (5.9 mmol) of (i-Pr),Sz was used. The product was recrystallized from hexane at -78 "C to give orange needles: yield 50%; mp 34-35 "C; MS, m / e (relative intensity) 56 (35, Fe), 121 (78, FeCp), 244 (48, M+ - CH(CH,NMe,), 286 (60, M+ - "Me,), 331 (35, M'). Anal. Calcd for CI7Hz5FeNS:C, 61.63; H , 7.55; S, 9.67. Found: C, 61.70; H, 7.75; s, 9.90. ( R ,S )-1-[ 1-(Dimethy1amino)ethyll-2-( phenylthio)ferrocene (15, R = Ph). Amine (R)-4 (1.5 g, 5.8 mmol) was dissolved in 30 mL of dry ether and placed in a 200-mL roundbottomed flask equipped with a side arm. The solution was cooled

Honeychuck et a1 to -40 "C, and 4.0 mL (6.4 mmol) of n-BuLi was added slowly via syringe. The orange suspension was allowed to reach room temperature and stirred overnight. Ph,S2 (1.29 g, 5.91 mmol), dissolved in 30 mL of warm hexane, was added dropwise via cannula to the orange suspension at -78 "C. The resulting solution was allowed to reach 25 O C and then heated under reflux overnight. The reaction mixture was cooled, and 20 mL of H,O was added. The organic layer was separated, dried, and evaporated to give a dark oily residue. Unreacted Ph,S2 was removed by sublimation. The oil was chromatographed on activated alumina, by eluting first with hexane and then with CH2Cl,, to give the product: yield 55%; mp 40-41 "C; MS, m / e (relative intensity) 56 (45, Fe), 72 (100, CH(CH,)NMe,), 121 (54, FeCp), 212 (31), Anal. Calcd for 320 (78, Mt - "Me,), 365 (70, M'). C,,H,,FeNS: C, 65.75; H, 6.30. Found: C, 65.32; H, 6.21. (R,S)-1-[1-(Dimethylamino)ethyl]-2-(benzylthio)ferrocene (15, R = CH,Ph). The procedure was the same as for 15, R = Ph, except that 1.45 g (5.88 mmol) of (PhCH,),S, was used. The product was obtained as a brown oil: yield 0.90 g (60%); IR (neat) 1490, 3000-3090 cm-'; MS, m / e (relative intensity) 56 (54, Fe), 72 (84, CH(CH,)NMe,), 91 (100,CH,Ph), 121 (57, FeCp), 244 (39), 334 (54, Mt - "Me,), 379 (25, Mt). Anal. Calcd for C21H25FeNS:C, 66.49; H, 6.60. Found: C, 66.52; H, 6.65. ( S ,R )-1-[ l-(Dimethylamino)ethyl]-2-(phenylseleno)ferrocene (16). A hexane solution of n-BuLi (2.7 M, 4.0 mL, 11 mmol) was added to a solution of 3.43 g (13.3 mmol) of (S)-4 in 150 mL of dry ether a t -78 "C over a period of 30 min. The suspension was stirred for 12 h at 25 "C and cooled to -78 "C, and then 3.40 g (11.0 mmol) of Ph,Se, in 40 mL of ether was added dropwise over a 30-min period. The reaction mixture was stirred under Nz for 3 h at 25 "C and filtered. The filtrate was washed with H 2 0 , and the organic layer was separated and evaporated to a brown oil. The oil was separated on a silica gel column by gradient elution (hexane/benzene/ether), giving 16 as brown crystals: yield 60%; mp 45-46 "C; IR (neat) 460, 504, 540, 685, 730,818,925,962,1000,1020,1102,1150,1190,1240,1260,1364, 1480,1580,2770,2810,2850,2930,2965,305~3090 cm-'; MS, m/e (relative intensity) 44 (89, NMe2), 56 (63, Fe), 121 (77, FeCp), 212 - Se), 368 (100, Mt (16. vinylferrocene), 288 (38, M+ - "Me, - "Me,). Anal. Calcd for C,,H,,FeNSe: C, 58.28; H, 5.62. Found: C, 58.25; H, 5.77. 1,l'-Bis(methylse1eno)ferrocene (17, R = Me). A solution of TMEDA (1.28 g, 11.0 mmol) and 2.7 M n-BuLi in hexane (4.1 mL, 11 mmol) was added over a half-hour period to 1.0 g (5.3 mmol) of ferrocene in 50 mL of dry ether under argon in a 150-mL round-bottomed Schlenk flask. The mixture was stirred for 3 h at room temperature, and a solution of MezSe, (2.07 g, 11.0 mmol) in 20 mL of dry ether was added dropwise at -78 "C. The mixture was stirred for 12 h at room temperature and filtered. The filtrate was washed with HzO, and the organic layeer was separated and evaporated to a brown oil. The oil was separated on a silica gel column by gradient elution (hexane/ether). The products obtained were yellow-brown plates (10.2 70yield, monosubstituted compound 18) and a dark brown oil (51.4% yield, disubstituted compound 17, R = Me). For 17, R = Me: 'H NMR 6 2.15 (s, 6 H, CH,), 4.20 (m, 4 H , H,, H4),4.31 (m, 4 H, H2,H5); I3C NMR 8.9 (4, Me), 71.2 (d, C2, CJ, 75.0 (d, C3, C4),75.5 (s, CJ; IR (neat) 500, 616,823,883,910,1023, 1054,1155, 1278, 1305, 1375, 1420, 2820, 2938, 3010,2100 cm-'; MS, m/e (relative intensity) 56 (100, Fe), 65 (5, C,H,), 95 (13, SeMe), 121 (49, C5H5Fe),184 (32, M' - 2 SeMe), 264 (11, Mt - SeMe - M e ) , 344 (24, Mt - 2 Me), 359 (8, M+ - Me), 374 (33, M+). Anal. Calcd for Cl2HI4FeSe2: C, 38.76: H, 3.79. Found: C, 39.04; H , 3.93. 1,l'-Bis(phenylse1eno)ferrocene (17, R = Ph).A solution of TMEDA (1.28 g, 11.0 mmol) and 2.7 M n-BuLi in hexane (4.1 mL, 11 mmol) was added over a half-hour period to 1.0 g (5.30) of ferrocene in 50 mL of hexane under Nz in a 150-mL Schlenk flask. The mixture was stirred for 3 h at room temperature, and a solution of Ph,Se2 (3.43 g, 11.0 mmol) in 20 mL of ether was added dropwise at -78 "C. The mixture was stirred for 12 h at room temperature and filtered. The filtrate was washed with H2O and the organic layer was separated and evaporated. Unreacted ferrocene was removed by sublimation. The product was recrystallized from benzene/hexane giving orange plates: yield 80.07~;mp 147-149 "C; 'H NMR 6 4.33 (t,4 H , H3, H4),4.47 (t, 4 H. H?. Hi), 7.00-7.41 (m, 10 H , Ph); IR (Nujol, CsI) 466, 493,

New Ferrocenyl Thio- a n d Selenoether Ligands 685,729,820,1010,1150, 1575 cm-'; MS, m / e (relative intensity) 56 (40, Fe), 121 (10, CpFe), 264 (14, M+ - SePh - Ph), 498 (38, M+). Anal. Calcd for C2,H18FeSe2: C, 53.27; H, 3.66. Found: C, 53.23; H , 3.55. (Methylse1eno)ferrocene (18). A 2.7 M solution of n-BuLi in hexane (4.1 mL, 11 mmol) was added to a solution of bromoferrocene,' (2.91 g, 11.0 mmol) in 150 mL of dry ether at -78 "C under argon in a 250-mL round-bottomed Schlenk flask equipped with a magnetic stirring bar. T h e suspension was stirred for 30 min a t 0 "C, and then a solution of MepSez(2.07 g, 11.0 mmol) in 20 mL of ether was added dropwise over a 30-min period a t -78 "C. The mixture was further stirred for 24 h and filtered. The filtrate was washed with ice water, and the organic layer was separated and evaporated to a brown oil. The oil was separated on a silica gel column with hexane to give the product as yellow-brown plates: yield 70.3%; mp 34-36 "C; 'H NMR 6 2.14 (s, 3 H, Me), 4.18 (m, 7 H, C5H5,H3, H,), 4.32 (m, 2 H, H,, H5); 13C NMR 6 9.0 (4, Me), 69.8 (d, C,, C5), 70.0 (d, C5H5),73.9 (d, C3, C4), 74.4 (s, Cl); IR (Nujol) 500, 820, 885, 1005, 1022, 1110, 1155, 1270, 1305 cm-'; MS, m / e (relative intensity) 56 (66, Fe), 65 ( 7 , C5H5),95 (13, SeMe), 121 (75, C5H5Fe),185 (4, M+ - SeMe), 265 (82, M+ - Me), 280 (63, M+). Anal. Calcd for Cl1Hl,FeSe: C, 47.36; H, 4.34. Found: C, 47.10; H , 4.51. [ 1-[(Dimethylamino)methyl]-2-(isopropylthio)ferrocene]palladium Dichloride (19). A 125-mL Erlenmeyer flask with a stir bar was placed in an oil bath at 100 "C. To this was added 1.00 g (3.07 X mol) of K2PdC14in 75 mL of H,O. mol) of 14, R = LPr, in 45 mL A solution of 0.973 g (3.07 X of acetone was added dropwise over 15 min. The mixture was heated for 10 min and left overnight a t 25 "C. Filtration and washes with 20 mL of H 2 0 and 10 mL of hexane gave fine brown crystals of the product: yield 0.902 g (59.6%); mp 165-167 "C; IR (Nujol, CsI) 300, 331,469, 718,814,992, 1103,1168 cm-'; MS, m / e (relative intensity) 43 (41, i-Pr), 44 (55, NMe,), 56 (21, Fe), 58 (18, CH,NMe,), 65 (24, C5H5),106 (2, Pd), 121 (26, C5H5Fe), 196 (4, M+ - C5H5Fe- PdCl,), 242 (15, M+ - S-i-Pr - PdCl,), 273 (6, M+ - NMe, - PdCl,), 274 ( 7 , M+ - i-Pr - PdCl,), 317 (20, M+ - PdCl,). Anal. Calcd for ClGHz3FeNSPdCl2: C, 38.86; H, 4.69. Found: C, 38,98; H, 4.57. ( R ,S ) - [ 1-[1-( D i m e t h y 1 a m i n o ) e t h y l l - 2 - ( p h e n y l t hio)ferrocene]palladium Dichloride (20). Complex 20 was prepared from a benzene solution of (PhCN),PdC12 and (R,S)-amine thioether 15, R = Ph. The molar ratio of (PhCN),PdC12:15, R = Ph, was 1:l.l. The reaction mixture was stirred for 10 h, and the resulting precipitate was filtered, washed with benzene and then petroleum ether, and recrystallized from CHzCl,/hexane by slow evaporation to give greenish black crystals; yield 85%; mp 165-166 "C dec. Anal. Calcd for CzoH23FeSNPdClz:C, 44.25; H, 4.24. Found: C, 44.18; H , 3.96. ( S , R ) - 1-[ [ l-(Dimethylamino)ethyl]-2-(phenylseleno)ferrocene]palladium Dichloride (21). T o a solution of 0.383 g (1.00 mmol) of (PhCN),PdCl, in 10 mL of benzene was added a solution of 0.413 g (1.00 mmol) of @&amine selenoether 16 in 20 mL of benzene. After 20 h of stirring at room temperature, the dark brown precipitate formed was collected by filtration, washed with benzene, and dried in vacuo. The precipitate was recrystallized from CH,Cl,/hexane to give 21 as dark brown needles: yield 70%; mp 16C-162 "C; IR (Nujol, CsI) 305,330,467, 493,518,538,685,740,830,900,1000,1020,1104,1170,1247,1304, 1578 cm-'; MS, m / e (relative intensity) 44 (83, NMe,), 56 (12, Fe), 121 (8, FeCp), 212 (2, vinyl ferrocene), 288 (1,M+ - PdC1, - "Mez - Se), 368 (1, M+ - PdC1, - "Me,). Anal. Calcd for C,J-IH,3FeSeNPdC1,: C, 40.75; H, 3.93. Found C, 41.31; H , 3.69. [ 1,l'-Bis(phenylseleno)ferrocene]palladium Dichloride (22). T o a solution of 0.383 g (1.00 mmol) of (PhCN),PdCl, in 10 mL of benzene was added a solution of 0.498 g (1.00 mmol) of 1,l'-bis(phenylse1eno)ferrocene (17, R = Ph) in 20 mL of benzene. After 12 h of stirring at room temperature, the reddish brown precipitate formed was collected by filtration, washed with benzene, and dried in vacuo. The precipitate was recrystallized from CH,Cl,/hexane to give 22 as brick red needles: yield 85%; mp 195-197 "C dec; IR (Nujol, CsI) 270,302,345,460,482,500,

Organometallics, Vol. 5, No. 3, 1986 485 685, 730, 836, 1000, 1020 cm-'; MS, m / e (relative intensity) 44 (7, NMe,), 56 (42, Fe), 65 (11,Cp), 121 (17, CpFe), 184 (3, M+ - PdCl, - 2 SePh), 498 (2, M+ - PdCl,). Anal. Calcd for C,,Hl,FeSezPdC1,: C, 39.24; H, 2.69. Found: C, 38.97; H , 2.58. [ 1- [ ( D i m e t h y 1a m i n 0 ) m e t h y 11- 2 - ( m e t h y l s e l e n 0 ) -. ferrocene]palladium Dichloride (23, R = Me). T o a solution of 0.383 g (1.00 mmol) of (PhCN),PdCl, in 10 mL of dry benzene was added a solution of 0.336 g (1.00 mmol) 13, R = Me, in 20 mL of dry benzene. After 20 h of stirring at room temperature, the red-brown precipitate formed was collected by filtration, washed with benzene, and dried in vacuo. The powder was recrystallized from CH,Cl,/hexane to give 23, R = Me, as dark brown crystals: yield 75%; mp 182-184 "C; 'H NMR 6 2.32 (s, 3 H, SeMe), 2.75 (5, 3 H, NMe), 2.80 (d, J = 13 Hz, 1 H , NCH), 3.11 (s, 3 H, NMe), 4.00 (d, J = 13 Hz, 1 H, NCH), 4.24 (s, 5 H , C5H5),4.38, 4.50 (m, 3 H, H3, H4, H5);13C NMR 6 19.3 (9, SeMe), 48.5 (q, NMe), 54.9 (q, NMe), 65.8 (t, NCH,), 68.5 (d, C3, C4,C5), 69.1 (d, C3, C4, C5), 70.5 (4C3, C4, C5), 71.5 ( 4 C&), 82.0 (s, Cz), 91.4 (s, CJ; IR (Nujol) 263, 320,470, 498, 510, 520, 530, 678, 830, 995,1078, 1102,1160, 1242 cm-'; MS, m / e (relative intensity) 44 (100, NMe,), 56 (24, Fe), 58 (59, CH,NMe,), 65 (41, C5H5),95 (22, SeCH,), 106 (12, Pd), 121 (40, C5H5Fe),242 (27, M+ - SeCH, PdCl,), 293 (5, M+ - NMe, - PdCl,), 337 (16, M+ - PdC1,). Anal. Calcd for C14Hl,C1,FeNPdSe: C, 32.76; H , 3.73. Found: C, 32.47; H, 3.65. [ 1-[(Dimethylamino)methyl]-2-[ (4-~hlorophenyl)seleno]ferrocene]palladium Dichloride (23, R = 4-Chlorophenyl). To a solution of 0.383 g (1.00 mmol) of (PhCN),PdCl, in 10 mL of dry benzene was added to a solution of 0.433 g (1.00 mmol) of 13, R = 4-chlorophenyl, in 20 mL of dry benzene. After 20 h of stirring at room temperature, the gold-brown precipitate formed was collected by filtration, washed with benzene, and dried in vacuo. The product was recrystallized from CH2Cl,/hexane to give 23, R = 4-chlorophenyl, as dark brown needles: yield 83%; mp 162-164 "C dec; 'H NMR 6 2.45 (s, 3 H , NMe), 2.83 (d, J = 14 Hz, 1 H, NCH), 3.13 (s, 3 H, NMe), 4.10 (d, J = 14 Hz, 1 H , NCH), 4.16 (m, 1 H, H3, H,, H5), 4.32 (m, 1 H , H3, H,, H5), 4.34 (s, 5 H , C5H5),4.41 (m, 1 H, H3, H,, H5), 7.35-7.83 (m, 4 H , Ph); IR (Nujol, CsI) 260, 324,472, 290, 520, 540, 810,840, 1012, 1092, 1110, 1180, 1240, 1266 cm-'; MS, m / e (relative intensity) 44 (62, NMe,), 56 (16, Fe), 58 (16, CH2NMe,), 65 (34, C5H5),106 (5, Pd), 121 (35, C5H5Fe), 190 (18, SeC6H4Cl),242 (20, M+ - PdC1, SeC,H,Cl), 389 (2, M+ - NMe, - PdCl,), 433 (3, M+ - PdCl,). Anal. Calcd for ClgH,,C13NSeFePd: C, 37.42; H , 3.31. Found: C, 36.57; H, 3.46. P a l l a d i u m Complexes 19-23. Palladium complex 19 was made by using the same procedure as for o-(methylthi~)aniline.~~ An acetone solution of the ferrocene was added dropwise to a hot aqueous solution of potassium tetrachloropalladate. The acetone boiled off, and the product precipitated immediately as fine brown crystals with a clearly defined melting point of 165-167 "C. Complexes 20-23 were made by using (PhCN),PdCl, as the source of Pd. Precipitates formed after several hours of stirring. Amine complexes 1 S 2 1 did not give simple 'H NMR spectra. Deposition of a black precipitate began immediately on dissolution in chloroform-d (possibly P d metal). Compounds 23 gave satisfactory NMR data. Hydrogenation of 1,3-Cyclooctadiene w i t h 19 i n CH,Cl, at 101 psi. Ferrocene-palladium complex 19 (0.010 g, 2.0 X mol), methylene chloride (9.0 mL), and 1,3-cyclooctadiene (1.00 mL, 0.00815 mol) were added to a 100-mL pressure bottle with a pressure gauge and stirring bar. The bottle was evacuated and filled several times with H, to a pressure of 101 psi. No H, uptake was observed in 27.4 h, so 0.0036 mL (2.0 X IO-, mol) of H 2 0 was added and the bottle was refilled with H,. Uptake began immediately and slowed after absorption of 0.00815 mol of H,.The initial turnover rate was 27 mol/mol of Pd/h. Hydrogenation of 1,3-Cyclooctadiene w i t h 19 i n Acetone at 14.7 psi. Ferrocene-palladium complex 19 (0.010 g, 2.0 X mol), acetone (9.0 mL), and 1,3-~yclooctadiene(1.00 mL, 0.00815 mol) were added to a 100-mL round-bottomed magnetically stirred flask on a 1-atm hydrogenation line fitted with a mercury manometer. The system was evacuated and filled several times with Hz to 1 atm. Uptake began after the red solution became redbrown. The turnover rate in the linear region was 1.9 mol/mol of P d / h . Product analysis at the end of reaction showed 0%

486

Organometallics, Vol. 5, No. 3, 1986

1,3-cyclooctadiene, 100% cyclooctene, and 0% cyclooctane. Hydrogenation of 1,3-Cyclooctadiene with 19 in Acetone at 61 psi. Ferrocene-palladium complex 19 (0.010 g, 2.0 X mol), acetone (9.0 mL), and 1,3-cyclooctadiene (1.00 mL, 0.00815 mol) were added to a 100-mL pressure bottle with a pressure gauge and stirring bar. The bottle was evacuated and filled several times with H2 to a pressure of 61 psi. Uptake began immediately and slowed after absorption of 0.0055 mol of H,. The initial turnover rate was 422 mol/mol of Pd/h. Product analysis at the end of reaction showed 6.5% 1,3-cyclooctadiene,72.4% cyclooctene, and 21.1% cyclooctane. Isomerization-Hydrogenation of 1,5-Cyclooctadienewith 19. Ferrocene-palladium complex 19 (0.010 g, 2.0 X lo-' mol), acetone (9.6 mL), and 1,5-cyclooctadiene (0.50 mL, 0.0041 mol) were added to a 100-mL pressure bottle with a pressure gauge and stirring bar. The bottle was evacuated and filled several times with H, to a pressure of 60 psi. Uptake began immediately and ceased after absorption of 0.0025 mol of H,. The initial turnover rate was 9.0 mol/mol of Pd/h. Product analysis a t the end of reaction showed 17.0% 1,5-cyclooctadiene, 10.2% 1,4-cyclooctadiene, 10.0% 1,3-cyclooctadiene, 52.4 3' % cyclooctene, and 10.4% cyclooctane. Grignard Cross-CouplingReaction with Thioether-Palladium Complex 20 and Allylmagnesium Chloride To Give 4-Phenyl-1-pentene. Complex 20 (0.0271 g, 0.0499 mmol) was placed in a 100-mL round-bottomed Schlenk flask equipped with a stirring bar and a septum. The vessel was evacuated and filled with Ar several times. After being cooled to -78 "C, the reaction vessel was charged with 1.41 g (10.0 mmol) of 1-phenylethyl chloride in 20 mL of dry ether and stirred for 2 h a t room temperature before addition of allylmagnesium chloride (920 mmol, 10 mL at 2 M solution in THF) via syringe at -78 "C. The reaction mixture was allowed to warm to 0 "C, stirred for 40 h, and hydrolyzed with 10% HCI. The organic layer and ether extracts from the aqueous layer were combined, washed with saturated NaHCL3 solution and water, and dried over NazS04. Evaporation of solvent and chromatography on a silica gel column gave 1.32 g (93%) of 4-phenyl-1-pentene: 'H NMR 6 1.25 (d, 3 H , CH,), 2.35 (m, 2 H, CH2j, 2.80 (m, I H, CHCH,), 5.00 (m, 2 H, CH= CHz),5.70 (m, 1 H , CH=CH,), 7.25 (m, 5 H , Ph) [lit.28'H NMR 6 1.24 (d, 3 H, CH3), 2.32 (m, 2 H, CHz), 2.75 (sex, 1 H, CHCHJ, 4.80 (s, 1 H, CH=CH,), 4.92 (split d, 1 H , CH=CHJ, 5.52 (m, 1 H, CH=CH,), 7.00 (5 H, Ph)]; MS, m / e (relative intensity) 41 (5, CH,CH=CHZ), 77 (15, CGHc,), 105 (100, PhCHCH?), 146 (15, M+). Grignard Cross-Coupling Reaction with SelenoetherPalladium Complex 21 and Allylmagnesium Chloride To Give 4-Phenyl-I-pentene. The procedure was identical with that above employing 20, with substitution of 22.7 mg (0.0385 mmol) of 21 for 20. After the allylmagnesium chloride was added at -78 "C, the reaction mixture was stirred at 10 "C for 25 h. Workup as above gave 1.30 g (91.6%) of 4-phenyl-1-pentene with a proton NMR identical with that from 20. Grignard Cross-Coupling Reaction with SelenoetherPalladium Complex 21 and Allylmagnesium Bromide To Give 4-Phenyl-I-pentene. The procedure was identical with that above employing 20, with substitution of 27.6 mg (0.0468 mmol) of 21 for 20 and 20 mmol (20 mL of a 1 M ether solution) of allylmagnesium bromide for allylmagnesium chloride. Workup gave 1.39 g (98%) of 4-phenyl-I-pentene.

Results and Discussion Alkyl disulfides, phenyl disulfide, methyl diselenide, a n d aryl diselenides react w i t h 1-[(dimethylamino)methyl]-2lithioferrocene (2) and 1-[1-(dimethy1amino)ethyll-2lithioferrocene ( 5 ) , yielding ferrocenyl sulfides 14 and 15 and ferrocenyl selenides 13 and 16. Dilithioferrocene 8 reacts with methyl and phenyl diselenide to give ferrocenyl selenides 17. Ferrocenyllithium (1 1) w i t h m e t h y l diselenide yields selenide 18. B i d e n t a t e ligand 14, R = i-Pr, forms a PdCI2 complex that isomerizes 1,5-cyclooctadiene t o 1,3-cyclooctadiene u n d e r homogeneous conditions a n d selectively hydrogenates 1,3-cyclooctadiene to cyclooctene u n d e r homogeneous a n d heterogeneous conditions. The

Honeychuck e t al.

1.

.

#

65

,

. ~

I

~

~

C

I

I

I

C

L

I. . I . t. . ~ . . . . . . . . . . . . . . . . . . . . . . .

3

4

2

0

I

Figure 1. 250-MHz 'H NMR (chloroform-d, Me,Si) of 14 (R = Et). PdC1, complexes of 15, R = P h , and 16 are effective G r i g n a r d cross-coupling a g e n t s coupling l - c h l o r o - l p h e n y l e t h a n e w i t h allylmagnesium bromide and allylmagnesium chloride. Disubstituted selenoferrocene 17, R = Ph, and a m i n e selenoethers 13 (R = Me and 4-chlorophenyl) react with (PhCN)2PdCl, t o give PdC12complexes 22 and 23, R = M e and 4-chlorophenyl, respectively.

13. R =Me, Ph. and 4-chlorophenyl

(R,R)-5

14, R = Me, Et, i - P r # ,'-Bu. isopentyl, and Ph EH3

RSSR

SR

15, RmMe. Et, i - P r , P h , and CH2Ph ( SS)-5

CYSePh

PhSoSoPh

2

c H3 16 RSISOR

8

a S Y R R 17. R Me and Ph 9

11

MISISOMI

aseMe kJ

18

Ferrocenyl Sulfides and Selenides 13-18. Tables I and I1 p r e s e n t 250-MHz 'H NMR data for c o m p o u n d s 13-16. The spectrum of 14, R = Et (Figure l),is typical of the given data. The m o s t striking f e a t u r e of this s p e c t r u m is t h e large shift (0.39 p p m ) between the t w o diastereotopic protons of t h e aminomethylene group in t h e 3-4 p p m region. The value of Av/f19 here is 7.5, resulting in two clearly defined doublets. In phenylthio derivative 14, R = P h , Au/J = 1.0, and in phenylseleno derivative 13, R = Ph, A v / J < 1.0. These a r e cases in which the outside peaks are s m a l l and n o n e x i s t e n t , respectively. T h e m e t h y l e n e protons of 13, R = Ph, therefore a p p e a r as singlets. The large shift between aminomethylene protons, as in compounds 14, R = alkyl, has also been exhibited in (29) Silverstein, R. M.; Bassler, G. C.; Morrill, T. C. "Spectrometric Identification of Organic Compounds", 4th ed.; Wiley: New York, 1981.

Organometallics, Vol. 5 , N o . 3, 1986 487

N e w Ferrocenyl T h i o - and Selenoether Ligands

Table I. 250-MHz IH NMR Data for (~5-CsH5)Fe(~5-C5H3-1-CHzNMe2-2-ER) (13 a n d 14) i n CDC13/Me4Si [ 6 ( J , Hz)] CHXH. ---

compd FeCpC5H3(CH2NMez)(SeMe)

hi&--

CH3 2.12 s

CH

NMe2 2.20 s

FeCpC5H3(CH2NMe2)(SePh)

2.04 s

FeCpC5H3(CHzNMez)(Se-4-C1Ph)

2.03 s

FeCpC5H3(CH2NMe2)(SMe)

2.31 s

2.27 s

2.19 s

FeCpC5H3(CH2NMe2) (SEt)

FeCpC5H3(CH2NMe2)(S-i-Pr)

1.15 d 1.19 d FeCpC5H3(CH2NMe2)(S-i-Bu)0.94 d 0.99 d 0.99 d FeCpC5H3(CH2NMe2)(S-i-pent) 0.85 d

(6) (7) (7) (7) (7) (7)

3.02 m

2.18 s

1.77 h (7) 2.19 s 1.42 m 1.65 m

1.42 m

2.19 s 2.02 s

FeCpC5H3(CH2NMe2)(SPh)

NCH2 C5H5 C5H3 Ar 3.27 d (13) 4.10 s 4.18 t" 4.32 db 3.45 s 4.16 s 4.34 t' 7.00-7.90 m 4.46 m5 3.44 d(13) 4.42 dd" 4.46 dd" 3.73 d (13) 4.12 s 4.20 ma 4.35 ma 4.43 m" 2.64 m 3.21 d (13) 4.09 s 4.16 to 3.60 d (13) 4.32 db 3.14 d (13) 4.08 s 4.16 sa 3.61 d (13) 4.32 sb 2.45 dd (12.8) 3.20 d (13) 4.09 s 4.14 t" 2.45 dd (12.8) 3.20 d (13) 4.09 s 4.14 t" 2.62 dd (12.6) 3.61 d (13) 4.30 mb 2.59 ddd (12.87) 3.17 d (13) 4.08 s 4.14 tn 2.70 ddd (12.87) 3.62 d (13) 4.30 db 3.40 d (13) 4.16 s 4.32 to 6.98-7.17 m 3.46 d (13) 4.46 m" 4.51 m" SCH2

"1 H. b 2 H .

(6) for (qS-CSH5)Fe($-C5H3-l-CH(Me)NMe2-2-ER) (15 a n d 16) in CDC13/Me4Si NCCH? NMe, SCH? SCH, CHMel NCH C,H, C,H, Ph 1.40 d 2.13 s 2.30 s 3.94 q 4.10 s 4.25 m 1.35 d 2.10 s 2.60 q 3.95 q 4.10 s , 4.20 m 2.75 q FeCpC5H3[CH(Me)NMe2](S-i-Pr) 1.15 d 1.34 d 2.12 s 3.20 m 4.00 q 4.08 s 4.17-4.33 m 1.22 d 3.85 q 4.18 s 4.30-4.53 m 7.05-7.25 m FeCpC5H3[CH(Me)NMe2](SPh) 1.45 d 1.90 s FeCpC5H3[ CH (Me)NMez](SBz) 1.39 d 2.21 s 3.86-4.00 ma 2.21 s 4.06 s 4.10 m 7.18 m 3.86 q 4.16 s 4.20-4.50 m 7.00-7.50 m FeCpC5H3[CH(Me)NMe](SePh) 1.45 d 1.93 s

Table 11. 250-MHz 'H N M R Data compd SCCH? FeCpC5H3[CH(Me)NMez](SMe) FeCpC5H3[CH(Me)NMe2](SEt)1.15 t

Obscured.

Table 111. 13C NMR Data for (q6-CSH6)Fe(q5-C5H3-1-CHzNMe2-2-ER) (13 and 14) in CDC13/Me4Si (6) compd CH? CH CH,CHMe, SCH, NMe, NCH, Cs, C,, C, C,H, C, C, 45.1 q 58.1 t 9.6 q 68.4 d 69.8 d 75.1 s 87.2 s FeCpC5H3(CH2NMe2) (SeMe) 70.5 d 73.9 d 45.3 q 58.5 t 70.4 d FeCpC5H3(CH2NMe2) (Se-4-ClPh) 70.7 d 72.4 s 89.5 s 72.5 d 77.2 d FeCpC5H3(CHzNMe2) @Me)

20.2 q

FeCpC5H3(CH2NMez) (SEt)

14.8 q

FeCpC5H3(CH2NMe2) (S-i-Pr)

22.8 q 23.6 q

39.4 d

FeCpC5H3(CH2NMe2) (S-i-Bu)

21.8 q 22.3 q

28.5 d

FeCpC5H3(CH2NMe2) (S-i-pent)

22.1 q 22.4 q

27.2 d

44.2 q

56.6 t

45.1 q

57.2 t

45.3 q

57.3 t

46.3 t

45.2 q

57.3 t

38.6 t

45.2 q

57.3 t

45.0 q

56.7 t

30.7 t

35.1 t

FeCpC5H,(CH2NMe2)(SPh)(14)

a

Para.

* Meta.

Ortho.

68.0 d 70.8 d 71.9 d 67.4 d 70.6 d 73.7 d 67.6 d 70.9 d 75.1 d 67.5 d 70.6 d 73.3 d 67.4 d 70.7 d 73.6 d 69.0 d 71.3 d 75.6 d

70.0 d

83.6 s

84.3 s

69.8 d

80.5 s

87.0 s

69.6 d

79.0 s

88.0 s

70.0 d

81.9 s

87.1 s

69.9 d

81.2 s

87.2 s

70.3 d

76.4 s

87.6 s

Ar

129.4 d 131.9 d 132.1 s 134.6 s

124.8 d" 128.4 db 126.2 d' 140.1 sd

S-C.

1-[(dimethylamino)methyl]-2-(diphenylphosphino)ferrocene.30 Inversion of the pyramidal N of derivatives 13-16 is faster than the NMR time scale, so the nitrogen methyls (30) Marr, G.; Hunt,T. J . Chern. SOC.C 1969, 1070-1072.

appear as singlets in the 1.9-2.3 ppm region. Assignments of the substituted ring protons H3, H,, and H, in 13-16 have not been made since a number of s t ~ d i e s ~ of l-~~ (31) Rausch, M. D.; Siegel, A. J. Organornet. Chern. 1969,17,117-125. (32) Slocum, D. W.; Emst, C . R. Adu. Organornet. Chern. 1972, 10, 79-114.

488 Organometallics, Vol. 5 , No. 3, 1986

Honeychuck et a1.

Table IV. Homogeneous Selective Hydrogenation of Dienes to Monoenens initial rate, mol/mol of Pd / h/ psi 6.92 8.99 3.45-5.52 0.001 I

substrate 1,3-COD 1,3-COD isoprene 1 .I-cyclohexadiene

T , "C 27 22 22

65

metal Pd2+ Pdo PdO Pd2'

solv acetone to1uene toluene toluene

additive

ref this work 47 45

H*O

53

*COD = cyclooctadiene. Ligands vary from case to case. Complex 19 was used in the first entry.

monosubstituted ferrocenes have shown that a single substituent may deshield or shield positions 2 and 5 and may deshield or shield positions 3 and 4, in any combination relative to ferrocene. Carbon-13 NMR spectra of compounds 13 and 14 are given in Table 111. Since the molecules have a C1 symmetry due to planar ~hirality,~, groups such as isopropyl methyls are diastereotopic and appear at different chemical shifts. As in the proton spectra, the NMe2 carbons are equivalent due to fast inversion. Broad-band and either gated35,36or off-resonance decoupled spectra were recorded. Methyl singlets in the broad-band decoupled spectra appear as quartets in the gated or off-resonance decoupled spectra, methylenes as triplets, etc. Aside from the aryl carbons, the two most downfield peaks in Table I11 are due to substituted ring carbons C2 and C1, with the shift of C1 greater than that of C2 for Se analogue while C2 is greater than C, for S analogue. These assignments are firm and are based on the following observations: (1)the decoupled spectra reveal the two peaks as singlets (substituted carbons), (2) the Se-S change in Table I11 occurs in the C, column, not C2, and (3) C2 of 13, R = Me (Table 111) appears at 75.1 ppm, C1 of 17, R = Me (Experimental Section) at 75.5 ppm, and C1 of 18 (Experimental Section) a t 74.4 ppm. The constancy of chemical shift of the ring carbon atoms attached to selenium in these last three compounds in the face of the alternative assignment of 13, R = Me (87.2 ppm), provides particularly convincing evidence that the assignments are correct. Carbons 3 , 4 , and 5 in Table I11 are, on the other hand, difficult to assign, even on comparison with known assignments in [ (dimethylamin~)methyl]ferrocene~~ and with an extensive body of literature on polarization.^^^^^ The proton assignments H3, H,, and H5, if known, would be of no help. In some cases the chemical shift ordering is the same, but in ferrocenecaraldehyde, for example, the carbon order is C3 > C2;O whereas the proton order is H2 > H331-33 Comparison of 13, R = Me, and 14, R = Me, in Table I11 shows, as expected, that the inductive effect of Se is less than that of S. Carbons attached to Se appear upfield of analogous carbons attached to S (methyls, 6 9.6 and 20.2; (33) Slocum, D. W.; Ernst, C. R. Organomet. Chem. Reu. A 1970, 6, 337-353. (34) Testa, B. "Principles of Organic Stereochemistry"; Marcel Dekker: New York, 1979; Chapter 7 . (35) Gunther. H. "NMR Spectroscopy"; Wiley: Chichester, 1980;pp 359-360. (36) Levy, G. C.; Lichter, R. L.; Nelson, G. L. "Carbon-13 Nuclear Magnetic Resonance Spectroscopy", 2nd ed.; Wiley: New York, 1980; Chapter 1. (37) Koridze, A. A,; Petrovskii, P. V.; Mokhov, A. I.; Lutsenko, A. I. J . Organomet. Chem. 1977, 136, 57-63. (38) Bromilow, J.; Brownlee, R. T. C.; Craik, D. J.; Fiske, P. R.; Rowe, J. E.; Sadek, M. J . Chem. Soc., Perkin Trans. 2 1981, 753-759. (39) Craik, D. J.; Brownlee, R. T. C. Prog. Phys. Org. Chem. 1983,14, 1-73. (40) Koridze, A. A,; Mokhov, A. I.; Petrovskii, P. V.; Fedin, E. I. Izu. Akad. Nauk SSSR, Ser. Khim. 1974, 2156. (41) Rosenblum, M. "Chemistry of the Iron Group Metallocenes"; Wiley: New York, 1965; pp 37-40. (42) Lindoy, L. F.; Livingstone, S. E.; Lockyer, T. N. Aust. J . Chem. 1967, 20, 471-478.

3O'd

'

4

'

;'

;1

I6

'

io

'

d4

HOURS

Figure 2. H2uptake plot for the hydrogenation of 1,3-cyclooctadiene with 19 in acetone.

C2, 6 72.1 and 83.6). The infrared spectra of the compounds of this paper are given in the Experimental Section. Compounds 13, 15, 14, 16, and 18 obey the "1000,1100 rulew4'which states that ferrocenes containing an unsubstituted ring will have two peaks, one near 1000 cm-' due to C-H bend parallel to the C5H5ring and another near 1100 cm-' due to an antisymmetric C5H5 ring breathing mode. Thioethers have a C-S stretch near 660 cm-l, usually too weak to be of use,29as is the case here. The mass spectra of these compounds exhibit molecular ions, expected fragments, and smaller peaks consistent with isotopes 54Fe,57Fe,34S,and 7sSe. Hydrogenation and Isomerization by Using Palladium Complex 19. Hydrogenation by homogeneous catalysts is well developed.43 Of the many known complexes, those of group VI11 (8-1O6l) metals with amines and sulfides have been used with varying degrees of success. In 1967 PtCl, (SPhJ2 was found to be selective for the hydrogenation of dienes to monoenes in the presence of SnC12.44 Treatment of PdC12 or Na2PdC14with tertiary amines resulted in an active selective catalyst.& The same was true of PdClz when treated with 2,2'-bipyridine and NaBH,.46 Palladium chloride and thioethers gave complexes which, upon reduction by diisobutylaluminum hydride, were selective catalysts.47 The thioether-rhodium complex RhC13(SEt& hydrogenates maleic acid, provided maleic acid is present in e x c e ~ s . ~ ~ - ~ l (43) Parshall, G. W. "Homogeneous Catalysis"; Wiley: New York, 1980. (44) Tayim, H. A.; Bailar, J. C., Jr. J . Am. Chern. SOC.1967, 89, 4330-4338. (45) Frolov, V. M.; Parenago, 0. P.; Bonarenko, G. N.; Kovaleva, L. S.; El'natanova, A. I.; Shiukina, L. P.; Cherkashin, G. M.; Mirskaya, E. Y. Kinet. Katal. 1981,22, 1356-1357. (46) Shuikina, L. P.; El'natanova, A. I.; Kovaleva, L. S.; Parenago, 0. P.; Frolov, V. M. Kinet. Katal. 1981,22, 177-182. (47) Shuikina, L. P.; Cherkashis, G. M.; Parenago, 0. P.; Frolov, V. M. Dokl. Akad. Nauk SSSR 1981,257,655-659. (48) James, B. R.; Ng, F. T. T.; Rempel, G. L. Inorg. Nucl. Chem. Lett. 1968, 4, 197-199. (49) James, B. R.; Ng, F. T. T. J . Chem. Soc., Dalton Trans. 1972, 355-359. (50) James, B. R.; Ng, F. T. T. J . Chern. SOC.,Dalton Trans. 1972, 1321-1324. (51) Cross, R. J. Int. Reu. Sei.: Inorg. Chern., Ser. T w o 1974, 5, 147-170. (52) Chatt, J.; Leigh, G. J.; Storace, A. P. J . Chem. SOC.A 1971, 1380-1389.

N e w Ferrocenyl Thio- and Selenoether Ligands

Organometallics, Vol. 5 , No. 3, 1966 489

Scheme I. Proposed Mechanism for Grignard Cross-Coupling Reaction

E=S.Se

In view of the selective hydrogenation activity of amine-palladium and thioether-palladium complexes when treated with hydride reducing a g e n t ~ , 4a~number ~~l of similar procedures were tried by using ferrocene-palladium complex 19 and NaH2A1(OCHzCHzOCH3)2in various solvents a t various temperatures and pressures. Complex 19 was inactive in CHZCl2(without a reducing agent) at 101 psi but became active after 10 mol of H 2 0 per mol of Pd was added. This is a heterogeneous system with a black precipitate (possibly P d metal) which hydrogenates 1,3-cyclooctadiene to cyclooctene, but only a t a slow rate. The complex also forms an active heterogeneous system in acetone at 1atm. The original red solution became cloudy after 36 h and Hz uptake began. Here again, though, the rate was low. Hydrogenation of 1,3-cyclooctadiene became conveniently fast in acetone a t 61 psi. This is a homogeneous system with no H 2 0 or reducing agents, and reaction proceeds at a useful rate (422 mol/mol of Pd/h). As time passed the red solution became brown but remained homogeneous. Most of the product a t the end of reaction was cyclooctene, but some cyclooctane was present. The hydrogen uptake plot for the regction is given in Figure 2. Complex 19 isomerized and hydrogenated 1,5-cyclooctadiene according to 1,5-COD 1,4-COD 1,3-COD cyclooctene

-

-

-

This is a homogeneous reaction that proceeds a t a low rate. In order to assess its effectiveness as a selective hydrogenation catalyst, complex 19 is compared to previous homogeneous P d catalysts in Table IV. The initial rates have been normalized as much as possible by dividing by the number of moles of P d and the pressure. The catalyst

in this work and that of the second entry (PdCl2complexed by undecylamine, reduced by diisobutylaluminum hydride, and hydr01yzed)~Ihave rates of the same order of magnitude with 1,3-cyclooctadiene. The third (catalyst = PdClz complexes by t r i a l k y l a m i n e ~and ) ~ ~fourth [catalyst = (PhzPCH2Phz)PdC12]53 entries are not as comparable to this work as the second entry. As has been pointed rates and selectivities are affected most by substrates and to a smaller extent by ligands, oxidation state of the metal, and solvents. With this in mind, the catalyst in this work appears to be at least as fast as the amine catalyst in entry 3 and 3 orders of magnitude faster than the chelating bis(phosphine) in entry 4. It is possible that the homogeneous hydrogenation proceeds in acetone but not methylene chloride because the acetone replaces the amine or the thioether as a P d ligand. According to this scheme, Hz adds to the acetone-amine-Pd complex or acetone-thioether-Pd complex but not to the amine-thioether-Pd complex. The heterogeneous reaction with HzO and CHzClzmay proceed via hydrolysis of a Pd-Cl bond,47making a hydroxo ligand and HC1. The acid causes formation of an amine hydrochloride, which either precipitates directly or loses its ability to coordinate Pd. Grignard Cross-Coupling Reactions by Using Palladium Complexes 20 and 21. Since the first report in 1976 that Pd complexes catalyze the coupling of Grignard reagents with organic halides,” the method has been used on a variety of Grignard reagents and halogenated species. Kumada’s group has done important work with many (53) Stern, E. W.; Maples, P.K. J. Catal. 1972, 27, 120-133. (54) Yamamura, M.; Mirotani, I.; Murahashi, S.-I. J. Organornet. Chem. 1975, 91, C39-C42.

490

Organometallics 1986, 5, 490-499

ligands and substrate^,^^ and c h l ~ r o p y r i d i n e sbromo,~~ puring nucleoside^,^^ and iodine carborane% have also been used. In these papers, all of the P d donor atoms come from group VA (1561)(N and P). We have now expanded this to group VIA (1661) (S and Se).

Thioether-amine-palladium complex 20 catalyzed formation of 4-phenyl-1-pentene from l-phenyl-l-chloroethane and allylmagnesium chloride at 0 " C in high yield (93%) in 40 h. The selenium analogue 21 was just as effective (91.6% with allylmagnesium chloride at 10 O C for 25 h). Allylmagnesium bromide with 21 gave an even better yield (98%) after 40 h at 0 O C . These are homogeneous reactions. The postulated mechanism55a in phosphine-amine-palladium complexes involves breaking the N-Pd bond and making an N-Mg bond, while the P-Pd bond remains intact. The analagous situation here

involves an intact ion of a S-Pd or a Se-Pd bond. Although thioethers have a lower s-acceptor capacity than tertiary phosphine^,^^ the strength of the S-Pd bond, and presumably the Se-Pd bond, is still significant and results in high yields.60 Scheme I illustrates the proposed mechanism for the cross-coupling reaction. Registry No. 1, 1271-86-9;(R)-4,31886-58-5;(SI-4,31886-57-4; 7, 102-54-5;10,1273-73-0;13 (R = Me), 100113-86-8;13 (R = Ph), 100113-87-9;13 (R = 4-chlorophenyl), 100113-88-0;14 (R = Me), 12248-18-9;14 (R = Et), 100113-89-1;14 (R = i-Pr), 100113-90-4; 14 (R = i-Bu), 100113-91-5;14 (R = isopentyl), 100113-92-6;14 (R = Ph), 100113-93-7;15 (R = Me), 100113-94-8;15 (R = Et), 100113-95-9;15 (R = i-Pr), 100113-96-0;15 (R = Ph), 100113-97-1; 15 (R = CH2Ph),100113-98-2; 16, 100113-99-3;17 (R = me), 100114-00-9; 17 (R = Ph), 100114-02-1; 18, 100114-01-0; 19, 100165-36-4;20, 100165-37-5;21, 100165-38-6;22, 100165-39-7; 23 (R = Me), 100114-03-2;23 (R = 4-chlorophenyl),100165-40-0; Me2Se2,7101-31-7; Ph2Se2,1666-13-3;Me&, 624-92-0; Et2& 110-81-6;(i-Pr),S2,4253-89-8; ( ~ - B U ) 1518-72-5; ~ S ~ , Ph2S2,882-33-7; (4-~hlorophenyl)~Se~, 20541-49-5; (isopentyl)&$, 2051-04-9; (PhCHJ2S2, 150-60-7; K2PdC14, 10025-98-6; (PhCN)ZPdC12, 14220-64-5;1,3-cycloocatdiene,1700-10-3;cyclooctene, 931-88-4; cyclooctane, 292-64-8; 1,5-cyclooctadiene,111-78-4; 1,4-cyclooctadiene, 1073-07-0; I-phenylethyl chloride, 672-65-1; allylmagnesium chloride, 2622-05-1;4-phenyl-l-pentene,10340-49-5; allylmagnesium bromide, 1730-25-2.

(55) (a) Hayashi, T.; Mitsuo, K.; Fukushima, M.; Mise, T.; Kagotani, 1982,104, 180-186. (b) M.; Tajika, M.; Kumada, M. J.Am. Chem. SOC. Hayashi, T.; Okamoto, Y.; Kumada, M. Tetrahedron Lett. 1983, 24, 807-808. (c) Hayashi, T.; Konishi, M.; Kobori, Y.; Kumada, M.; Higuchi, T.; Hirotsu, K. J . Am. Chem. SOC.1984,106, 158-163. (56) Isobe, K.; Kawaguchi, S.Heterocycles 1981, 16, 1603-1612. (57) CongDanh, N.; Beaucourt, J.-P.; Pichat, L. Tetrahedron Lett. 1979, 3159-3162. (58) Zakharkin, L. I.; Kovredov, A. I.; Ol'shevskaya, V. A,; Shaugumbekova, Z. S. J . Organornet. Chem. 1982,226, 217-222.

(59) Murray, S. G.; Hartley, F. R. Chem. Reu. 1981,81, 365-414. (60) Efforts are under way to determine the enantiomeric excess present in the 4-phenyl-1-pentenemade in these reactions. (61) In this paper the periodic group notation (in parentheses) is in accord with recent actions by IUPAC and ACS nomenclature committees. A and B notation is eliminated because of wide confusion. Groups IA and IIA became groups 1 and 2. The d-transition elements comprise groups 3 through 12, and the p-block elements comprise groups 13 through 18. (Note that the former Roman number designation is preserved in the last digit of the new numbering: e.g., 111-3 and 13.)

CH3

I

PhCHCl t BrMgCH2CH=CHp

or CIMgCH2CH=CH2

20 or 21 €12 0 THF

rH3

PhCHCH2CH-CH2 95%

T-Facial Stereoselectivity Operational during Conversion of Isodicyclopentadienes to Metallocene Derivatives' Leo A. Paquette," Paulo F. T. Schirch, Susan J. Hathaway, Leh-Yeh H s u , ~ and Judith C. Gallucci2 Evans Chemical Laboratories, The Ohio State University, Columbus, Ohio 432 10 Received May 21, 1985

Reaction of the isodicyclopentadienide anion with Fe"(aca~)~(py),, RuC13,and OsC1, is shown to provide the corresponding metallocene derivatives. The first two complexes are unequivocally established to be the end result of exo complexation to both ligands. The air sensitivity of the osmocene derivative, particularly in solution, precluded its complete characterization. The reactions of 4-(dimethylamino)isodicyclopentafulvene with (~5-cyclopentadienyl)(~6-p-xylene)iron(II) hexafluorophosphate and ($-cyclepentadienyl)tris(acetonitrile)ruthenium(III) hexafluorophosphate were also investigated. In the first instance, a 65:35 mixture of exo- and endo-(~5-cyclopentadieny1)(~5-4-formyltricyclo[5.2.1.02~6]deca-2,4-dien-6-yl)iron (29 and 30) was produced after alkaline hydrolysis. These isomers were separated following conversion to their alcohols, with the respective three-dimensional structures being established by X-ray analysis of the dimeric ether derived from the major alcohol. In the ruthenium example, a higher proportion of the exo complex 35 (86 %) was obtained. Purification was achieved by recrystallization, allowing for crystallographic structural confirmation. Introduction The isodicyclopentadiene ring system (1) is of fundamental importance as the result of differing electronic (1) Electronic Control of Stereoselectivity. 32. For part 31, see: Paquette, L. A,; Kravetz, T. M.; Hsu, L.-Y. J . Am. Chem. SOC.1985, 107, 6598. (2) Authors to whom inquiries concerning the X-ray crystal structure analyses should be directed: L.-Y. Hsu for structures 21 and 33 and J. C. Gallucci for structure 35.

0276-7333/86/2305-0490$01.50/0

densities on the surfaces of its cyclopentadiene ring and the appreciable a-facial stereoselectivity exhibited during cycloaddition reaction^.^ That ground-state electronic influences are not identical above and below the dienyl

(3) (a) Paquette, L. A. In "Stereochemistry and Reactivity of Pi Systems"; Watson, W. H., Ed.; Verlag Chemie: Deerfield Beach, FL, 1983; pp 41-73. (b) Gleiter, R.; Paquette, L. A. Acc. Chem. Res. 1983, 16, 328.

1986 American Chemical Society