"Metalloazine" Complexes of Molybdenum and Zirconium - American

2717 at -20 "C. The cisltrans ratio calculated from integrated 'H NMR spectra was 30170. 7: IR (cm-', Nujol) 2025 (s, YCO), 1985 (m, VCO), 1930 (m, VC...
0 downloads 0 Views 918KB Size
Organometallics 1989,8, 2717-2723 at -20 "C. The cisltrans ratio calculated from integrated 'H N M R spectra was 30170. 7: IR (cm-', Nujol) 2025 (s, YCO), 1985 (m, VCO), 1930 (m, VCO). Anal. Calcd for CmHmF3Mo06SPSi: C, 48.78;H, 5.19. Found: -- -- C, 48.49;H, 4.98. trans-7: 'H NMR (CDzClz,27 "C) 6 12.80 (d, ,JpH = 8.2 Hz, 1 H, CHOSiMe,), 7.50 (m, 10 H, Ph), 2.01 (d, '-JPH = 8.5 Hz, 3 H, PMe), 1.77 (9, 15 H,C6Me5),0.01 (9, 9 H, SiMe,); 13C NMR (CDXl,. -60 "C) 6 341.69 (br. CHOSiMe3.238.10 (d. z J =~24.2 ". . Hz, Mi,131.0 im, Ph), 178164 (9, l~~~= 318 HZ; CFJ, 109.25 (9, C5Me5),18.0 (d, lJPc = 32.0 Bz, PMe), 10.87 (8,C&fe5), 1.02 (9, SiMe,); 31PNMR (CDZClz, -60 "C) 6 37.09 (s, PPhzMe). cis-7: 'H NMR (CD2Cl2,27 "c) 6 13.15 (d, 'JpH = 6.0 Hz, 1 H,CHOSiMe,), 7.50 (m, 10 H, Ph), 2.01 (d, 'JPH = 8.5 Hz, 3 H, PMe), 1.79 (9, 15 H,C6Mes),0.02 (9, 9 H, SiMe,); 13C NMR (CD2Cl2,-60 "C) b 341.69 (br, CHOSiMe,), 248.50 (d, 2 J p =~ 24.2 Hz, CO), 131.0 (m, Ph), 242.50 (d, 2 J p = ~ 7.0 Hz, CO), 178.64 (q,

2717

'JCF= 318 Hz, CF,), 109.66 (8, C6Me5),19.8 (d, 'Jpc = 31.8 Hz, PMe), 10.87 (8,C,Me5),2.16 (8,SiMe,); ,'P NMR (CD2C12,-60 "C) 6 54.50 (9, PPhzMe). Acknowledgment. We are grateful to Prof. M. J. McGlinchey (Hamilton, Canada) and Drs. J.-R. Hamon, V. Guerchais, and S. Sinbhandit (Rennes) for helpful discussions. We acknowledge M. J. Tudoret for skillful experimental assistance. A gift of molybdenum hexacarbonyl was generously provided by BASF (Ludwigshafen, West Germany). Supplementary Material Available: Complete tables of bond lengths and angles for 11and tables of positional parameters and general displacement parameter expressions (5 pages); a listing of observed and calculated structure factors (5 pages). Ordering informations is given on any current masthead page.

"Metalloazine" Complexes of Molybdenum and Zirconium Georgia M. Arvanitis, John Smegal, Ingrid Meier, Anthony C. C. Wong, Jeffrey Schwartz," and Donna Van Engen Department of Chemistry, Princeton University, Princeton, New Jersey 08544 Received July 26, 1988; Revised Manuscript Received June 7, 1989

A series of "metalloazines" of molybdenum and zirconium was prepared. Molybdenum metalloazines are obtained by reaction between diazo compounds and a molybdenum(1V)complex, OMo(DTC)2 (DTC = a dialkyldithiocarbamate), by oxidative addition. These species are electrophilicat the terminal carbon and add nucleophiles, including ylides. Zirconium metalloazines can be prepared by reaction between zirconium(II)phosphine complexes and diazo compounds, but they are better prepared by metathesis between Cp2ZrC12and hydrazone derivatives. These species behave as nucleophiles at carbon and condense with aldehydes or ketones to yield olefins. Several mechanistic studies were performed concerning olefination iising zirconium metalloazines;these suggest that olefiis are formed by a process of antiperiplanar approach of the carbonyl containing substrate to the metalloazine,giving preferentially the 2 olefin isomer. (A similar antiperiplanar approach is suggested for reaction between molybdenum metalloazines and ylides, given that 2 olefins predominate in this process, too.) Introduction Many transition-metal carbene complexes can be used for alkylidene group transfer: "nucleophilic" complexes have been found to alkylidenate carbonyl-containing materials,' and "electrophilic" ones can react with certain ylides in complementary synthetic procedures to give olefins.2 Conceptually, organic carbonyl-containing compounds might serve as the source of reactive alkylidene units in a metal complex. Our intent was to prepare a series of compounds, M=X=C(R1)R2, in which the [= X=C(Rl)R2] group could be obtained easily from aldehydes or ketones and for which reactivity paralleled that of their carbene complex analogues, M=C(R1)R2 (with facile loss of "X" in a condensation procedure). We have focused our attention on the chemistry of metallic derivatives of hydrazones since these materials are readily accessible and might mimic the reactivity of carbene com(1) For example, see: Tebbe, F. N.; Parshall, G. W.; Reddy, G. S. J. Am. Chem. SOC. 1978,100,3611. Pine, S. H.; Zahler, R.; Evans, D. A.; Grubbs, R. H. J. Am. Chem. SOC.1980,102,3270. Hartner, F. W., Jr.; Schwartz, J. J. Am. Chem. SOC. 1981,103,4979. Clift, S. M.; Schwartz, J. J. Am. Chem. SOC. 1984, 106, 8300. Kress, J.; Osborn, J. A. J. Am. Chem. SOC. 1987,109,3953. Aguero, A.; Kress, J.; Osborn, J. A. J A m . Chem. SOC. 1986,108,531. Schrock, R. R. J. Am. Chem. SOC. 1976,98, 5399. (2) For example, see: Fischer, E. 0. Angew. Chem.,Znt Ed. E 1 1964 3,580. Casey, C. P.; Burkhardt, T. J. J.Am. Chem. SOC. 1972,%;6543: Casey, C. P.; Bertz, S. H.; Burkhardt, T. J. Tetrahedron Lett. 1973,1421.

plexes, with extrusion of N2. In fact, elimination of N2 could provide a powerful driving force for reactions using these "metalloazine" derivatives. Molybdenum "Metalloazines" Molybdenum metalloa~ines~ (1) can be formed by reaction between low-valent molybdenum complexes and diazoalkanes which are obtained by partial oxidation of hydrazones. In forming the metalloazine the molybdenum center undergoes a formal oxidative addition of the diazo unit. A general synthesis of molybdenum "metalloazines" was accomplished by using O M O ' ~ ( S ~ C N which R ~ ) ~ can be obtained4from Na2Mo04-H20and N a S 2 C m followed by reduction with triphenylphosphine. The absence of N2 evolution during the reaction between O M O ( S ~ C Nand ~)~ diazoalkanes5and the formation of the expected hydrazone upon hydrolysis suggest the presence of the entire diazoalkane unit in l, which we formulate as OMo(S2CNR2)2(NNCR'Ft").Transition-metal complex adducts of diazoalkanes are well established,6 and a variety of (3) Smegal, J. A,; Meier, 1. K.; Schwartz, J. J.Am. Chem. SOC.1986, 108, 1322. (4) Chen, G. J.-J.; McDonald, J. W.; Newton, W. E.Znorg. Chem. 1976, 15,2612. Barral, R.; Bocard, C.; SBrCe de Roch, I.; Sajus, L. Tetrahedron Lett. 1972, 1693. (5) Kaufman, G. M.; Smith, J. A.; VanderStouw, G. G.; Shechter, H. J.Am. Chem. SOC.1965,87, 935.

0276-733318912308-2717$01.50/00 1989 American Chemical Society

2718 Organometallics, Vol. 8, No. 11, 1989 (M~VI)-N.N-(

Arvanitis et al.

- (M~v~)-N-N 3.0u(Fo)]. The structure was solved by conventional heavy-atom

Organometallics, Vol. 8, No. 11, 1989 2723

Metalloazine Complexes of Molybdenum a n d Zirconium methods (Patterson and Fourier) and was refined by blockedcascade least squares. All calculations were carried out using the SHELXTL program. In the final stages of refinement, anisotropic thermal parameters were used for the non-hydrogen atoms. The phenyl and cyclopentadienyl hydrogen atoms were located on a difference Fourier map and were entered a t idealized positions. The methyl hydrogens were not located. The hydrogen atoms were assigned isotropic temperature factors of B(H) = 1.2B(C). A hexane molecule of solvation, located on a difference Fourier map and refined with isotropic thermal parameters, is disordered around the 2-fold screw axis in the x direction. At convergence, R = 0.056 and R, = 0.057 for 2996 data and 409 variables. Reactions of Metalloazine Complexes with Organic Carbonyl Compounds. a. Reaction of [ C P ~ Z ~ N N C H P (2a) ~]~ with Cyclohexanone. To a solution of [CpzZrNNCHPhI2(0.068 g, 0.10 mmol) in T H F (2 mL) under argon was added cyclohexanone (12 pL, 0.095 mmol). The reaction was heated to 60 "C for 9 h. An aliquot (0.5 mL) was removed and hydrolyzed with a few drops of 5% KOH solution. The resulting pale yellow mixture was dried over KzCO3and filtered through Florisil. The products were analyzed by GC and GC-MS, and their identities were confirmed by comparison with samples prepared according to published procedures. b. Reaction of [CpzZrNNCHPhlzwith Cyclohexanone Derivatives. Reactions of [Cp2ZrNNCHPhI2with the organic carbonyl compounds 6 shown in Table I11 were carried out using the procedure and conditions described above. Products were analyzed by GC (6-ft 3% OV-17 column). Characterization data (or literature references) for olefiis 7 and mixed azines 8 are given in Table 111. Condensation reactions using other zirconium metalloazines28 were performed in similar fashion. Determination of the Rate of Reaction between [Cp2ZrNNCHPhI2(2a) and Cyclohexanecarboxaldehyde. To a solution of 2a (0.040 M, 0.750 mL, 0.030 mmol) in C,$, at 10 "C in a screw-capped NMR tube fitted with a Teflon septum was added dioxane (internal standard, 1.00 pL) and cyclohexanecarboxaldehyde (6.00 pL, 0.050 mmol). The reaction was monitored by NMR (Bruker, 250 MHz), programmed to store FIDs a t set time intervals. After 8 h, the NMR sample was removed from the probe and was allowed to reach room temperature. Tridecane was added as a GC standard, and the reaction mixture was worked up in the usual manner. Analysis by GC showed 7g (36%)and 8g (40%). NMR spectra were integrated relative to (22) Bestmann, H. J.; Kranz, E. Chem. Ber. 1969, 102, 1802. (23) Nifant'ev, E. E.; Zyk, N. V.; Koroteev, M. P. Zh. Obshch. Khim. 1975, 7, 1455. (24) Brewster, J. H.; Privett, J. E. J . Am. Chem. SOC.1966,88,1419. (25) Bestmann, H. J.; Lienert, J. Angew Chem.,Znt. Ed. Engl. 1969, 8, 763. (26) Lebedev, S. A.; Lopatina, V. S.; Luk'yanova, T. V.; Berestova, S.

S.;Shifrina, R. R.; Shapet'ko, N. N.; Petrov, E. S.;Beletakaya, I. P. Zh.

Om. Khim. 1985. 21. 721. 727) Naulet, N.; Martin, G. J. Tetrahedron Lett. 1979, 17, 1493. (28) Anal. Calcd for 2b (R,= H, Rz = p-CH@C&; Cl&,&OZr): C, H, N, Zr. For 20 (R,= H, Rz= p-ClC&; C1,H1&1NzZr): C, H, N. For 2e (R,= H, = p-CH&,H,; C18H18NzZr): C, H, N, Zr. For 2f (R1 = CH,, Rz = C,H,; C18H18N2Zr):C, H, N, Zr.

dioxane, and the areas obtained for [Cp2ZrNNCHPhlz,starting aldehyde, 1-phenyl-2-cyclohexylethene(7g), and CY-((cyclohexylmethy1ene)hydrazono)toluene (8g) were analyzed (using DATA.FOR program).% The plot for

1 Ao@o - X) k2t = (BO- A,) In BdAo - X)

was found to be linear within the initial phase of the reaction for the formation of both olefin and azhe (using a m3mR program). Least-squares analysis of the first 90 min of the reaction gave k2 (cc = correlation coefficient; int = intercept). (Data plots are available as supplementary material.) olefin k2 = 2.73 X cc = 0.984 int = 1.47 X

azine k2 = 2.23 X cc = 0.964 int = 1.97 X

Rates of reactions between metalloazine complexes 2a-d and cyclohexanecarboxaldehyde and between complex 2b and aldehydes 5a-d were determined according to the procedure described above. Data plots for rate calculations are available as supplementary material.

Acknowledgment. We acknowledge support for this work given by the National Institutes of Health and the National Science Foundation. Registry No. la, 100763-30-2; lb, 100789-89-7;IC, 100763-357; Id, 100763-36-8; 2a, 104531-96-6; 2a.1/2C,H8, 122844-61-5; 2b, 104548-75-6;2c, 122844-58-0;2a, 122844-59-1;sa, 104531-97-7; 3b, 122844-62-6;3c, 122844-63-7;3d, 122844-64-8;4,104531-98-8; 4'1/2C&14, 104531-99-9;6a, 108-94-1;6b, 583-60-8; 6c, 591-24-2; 6d, 589-92-4;6e, 5432-859; 6f, 98-53-3; 6g, 2043-61-0; 7a, 1608-31-7; (Z)-7b, 122822-39-3; (E)-7b, 122822-40-6; (Z)-~C, 122822-42-8; (E)-7c, 122822-43-9; 7d, 92377-88-3; 7e, 122822-46-2; 7f, 122822-48-4;7g, 5700-45-8;8a, 35430-51-4;8b, 122822-41-7;8c, 122822-44-0;ad, 122822-45-1;8e,122822-47-3;Sf, 122822-49-5; 8g, 104531-90-0;M O O ~ ( S ~ C N E19680-83-2; ~& MoO(SZCNELJ2, 25395-92-0; MoO(S2CNMez)2,39587-09-2; CpzZrC12,1291-32-3; PhHC(NJ, 766-91-6;MePhC(NJ, 22293-10-3;PhzC(Na,883-40-9; Ph,PCH(CH2)3CH3, 29541-98-8; Ph&NNCH(CH2)3CH3, 122822-38-2; H2NN=CH(4-MeOC6H4), 5953-85-5; HzNN=CH(4-ClCeH.J, 52372-80-2; HZNN=CH(4-NCCeH4), 87829-00-3; phenylhydrazone, 5281-18-5. Supplementary Material Available: Analytical data for la-d and 2a-f and X-ray diffraction data, including selected bond distances, bond angles, and atomic coordinates and isotropic thermal parameters for 2a and 4 and distances from mean planes for 4, an ORTEP diagram for 2a, and a representation of the unit cell for 4 (18 pages); tables of observed and calculated structural factors for 2a and 4 (31 pages). Ordering information is given on any current masthead. (29) The authors thank Mark Haner for providing VAX programs DATA.FOR

and XKIN.FOR.