Enantiopure planar chiral monomers and di-µ-bromo-bridged dimers of ferrocenylhydrazones from asymmetric cyclopalladation

Abstract

Planar chiral cyclopalladated ferrocenylhydrozones [P[upper bond 1 start][lower bond 1 start]dBr{(η⁵-C₅H₃CH[double bond, length half m-dash]N[upper bond 1 end][upper bond 1 start]N(CH₂)₃C[upper bond 1 end]HCH₂O[lower bond 1 end]CH₃)Fe(η⁵-C₅H₅)}]

(–)-(S_p,R) and (+)-(R_p,S ) and di-µ-bromo-bridged dimers [{P[upper bond 1 start]d[(η⁵-C₅H₃C(CH₃)[double bond, length half m-dash]N[upper bond 1 end][upper bond 1 start]N(CH₂)₃C[upper bond 1 end]HCH₂OCH₃)-

Fe(η⁵-C₅H₅)](µ-Br)}₂] syn-(–)-(S_p,R,R,S_p), syn-(+)-(R_p,R,R,R_p), syn-(+)-(R_p,S,S,R_p) and syn-(–)-(S_p,S,S,S_p) have been conveniently synthesized in enantiomerically pure form with a high level of diastereoselectivity and their absolute configurations elucidated by single-crystal X-ray analysis.

References

1. G. R. Newkome, W. E. Puckett, V. K. Gupta and G. E. Kiefer, Chem. Rev., 1986, 86, 451; J. Dupont, M. Pfeffer, J.-C. Daran and J. Gouteron, J. Chem. Soc., Dalton Trans., 1988, 2421; J.-P. Sutter, M. Pfeffer, A. de Cian and J. Fischer, Organometallics, 1992, 11, 386; M. Pfeffer, J.-P. Sutter, A. de Cian and J. Fischer, Organometallics, 1993, 12, 1167; C. López, R. Bosque, X. Solans, M. Font-Bardía, J. Silver and G. Fern, J. Chem. Soc., Dalton Trans., 1995, 2445.
2. (a) R. Bosque, C. López, J. Sales, J. Solans and M. Font-Bardía, J. Chem. Soc., Dalton Trans., 1994, 735; (b) S. Q. Huo, Y. J. Wu, C. X. Du, Y. Zhu, H. Z. Yuan and X. A. Mao, J. Organomet. Chem., 1994, 483, 139; (c) R. Bosque, C. López, J. Sales, D. Tramuns and X. Solans, J. Chem. Soc., Dalton Trans., 1995, 2445; (d) C. López, R. Bosque, D. Sainz, X. Solans and M. Font-Bardía, Organometallics, 1997, 16, 3261.
3. F. Maassarani, M. Pfeffer, G. L. Borgne, J. T. B. H. Jastrzebski and G. van Koten, Organometallics, 1987, 6, 1111.
4. L. G. Kuzmina, Yu. T. Struchkov, L. L. Troitskayoa, V. I. Sokolov and O. A. Reutov, Izv. Akad. Nauk SSSR, Ser. Khim., 1979, 95, 1528; G. Zhao, F. Xue, Z.-Y. Zhang and T. C. W. Mak, Organometallics, 1997, 16, 4023.
5. G. Zhao, Q.-G. Wang and T. C. W. Mak, Organometallics, 1998, 16, 3405.
6. G. Zhao, Q.-G. Wang and T. C. W. Mak, Tetrahedron: Asymmetry, 1998, 9, 1557.
7. C. López, R. Bosque, X. Solans and M. Font-Bardía, Tetrahedron: Asymmetry, 1996, 7, 2527.
8. A. I. Meyers and K. A. Lutomski, in Asymmetric Synthesis, ed. J. D. Morrison, Academic Press, 1984, vol. 3, p. 213; D. Enders, ibid., p. 275; O. Riant, O. Samuel and H. B. Kagan, J. Am. Chem. Soc., 1993, 115, 5835.
9. J. Granell, R. Moragas, J. Sales, X. Solans and M. Font-Bardía, J. Chem. Soc., Dalton Trans., 1992, 822; J. Granell, R. Moragas, J. Sales, M. Font-Bardía and X. Solans, J. Organomet. Chem., 1992, 431, 359; C. López, R. Bosque, X. Solans and M. Font-Bardía, J. Organomet. Chem., 1997, 535, 99.
10. G. Zhao and T. C. W. Mak, unpublished work.
11. J. Tanner and K. Krause, The Rigaku Journal, 1994, 11, 4; 1990, 7, 28; K. Krause and G. N. Phillips, jun., J. Appl. Crystallogr., 1992, 25, 146; M. Sato, M. Yamamoto, Y. Katsube, N. Tanaka and T. Higashi, J. Appl. Crystallogr., 1992, 25, 348.
12. T. Higashi, ABSCOR, An Empirical Absorption Correction Based on Fourier Coefficient Fitting, Rigaku Corporation, Tokyo, 1995.
13. SHELXL/PC Version 5.0 Reference Manual, Siemens Energy & Automation Inc., Madison, WI, 1996; G. M. Sheldrick, in Computational Crystallography 6, eds. H. D. Flack, L. Párkányi and K. Simon, International Union of Crystallography and Oxford University Press, 1993, p. 111.
14. J. D. Flack, Acta Crystallogr., Sect. A, 1983, 39, 876; H. D. Flack and D. Schwarzenbach, Acta Crystallogr., Sect. A, 1988, 44, 499.