Diphosphonites as highly efficient ligands for enantioselective rhodium-catalyzed hydrogenation

Abstract

Chiral ligands with achiral backbones such as ethano- or ferroceno-bridges linking two phosphonites derived from chiral diols such as binaphthol (BINOL) have been prepared; the corresponding Rh complexes are excellent catalysts in the hydrogenation of prochiral olefins such as itaconic acid dimethyl ester or 2-acetamido methyl acrylate, the ee values being 90–99.5%.

References

1. See for example: R. Noyori, Asymmetric Catalysis in Organic Synthesis, Wiley, New York, 1994, 1st edn; Catalytic Asymmetric Synthesis, ed. I. Ojima, VCH, New York, 1993.
2. Recent examples are: M. J. Burk, J. E. Feaster, W. A. Nugent and R. L. Harlow, J. Am. Chem. Soc., 1993, 115, 10125; A. S. C. Chan, W. Hu, C.-C. Pai and C.-P. Lau, J. Am. Chem. Soc., 1997, 119, 9570; P. J. Pye, K. Rossen, R. A. Reamer, N. N. Tsou, R. P. Volante and P. J. Reider, J. Am. Chem. Soc., 1997, 119, 6207; G. Zhu, P. Cao, Q. Jiang and X. Zhang, J. Am. Chem. Soc., 1997, 119, 1799; V. Enev, C. L. J. Ewers, M. Harre, K. Nickisch and J. T. Mohr, J. Org. Chem., 1997, 62, 7092; T. V. RajanBabu, T. A. Ayers, G. A. Halliday, K. K. You and J. C. Calabrese, J. Org. Chem., 1997, 62, 6012; G. Zhu and X. Zhang, J. Org. Chem., 1998, 63, 3133; F.-Y. Zhang, C.-C. Pai and A. S. C. Chan, J. Am. Chem. Soc., 1998, 120, 5808; Q. Jiang, Y. Jiang, D. Xiao, P. Cao and X. Zhang, Angew. Chem., 1998, 110, 1203; Angew. Chem., Int. Ed. Engl., 1998, 37, 1100; H. Doucet and J. M. Brown, Tetrahedron: Asymmetry, 1997, 8, 3775; C. Pasquier, S. Naili, L. Pelinski, J. Brocard, A. Mortraux and J. Agbassou, Tetrahedron: Asymmetry, 1998, 9, 193.
3. I. E. Nifantev, L. F. Manzhukova, M. Y. Antipin, Y. T. Struchkov and E. E. Nifant'ev, Russ. J. Gen. Chem., 1995, 65, 682 recent examples of chiral monophosphinates: D. Haag, J. Runsink and H. D. Scharf, Organometallics, 1998, 17, 398; J. Sakaki, W. B. Schweizer and D. Seebach, Helv. Chim. Acta, 1993, 76, 2654.
4. M. T. Reetz and A. Gosberg, patent applied for 1998.
5. Enantiomerically pure (R)- and (S)-BINOL are commercially available from Kankyo Kagaku Center (Japan) at a price of about $1300 per kilo.
6. We thank A. Meiswinkel for performing some of the experiments.
7. R. R. Schrock and J. A. Osborn, J. Am. Chem. Soc., 1971, 93, 2397.