High Performance of Rh(Phebox) Catalysts in Asymmetric Reductive Aldol Reaction: High Anti-Selectivity

J. Am. Chem. Soc., 127 (19), 6972 -6973, 2005. 10.1021/ja050698m S0002-7863(05)00698-0
Web Release Date: April 26, 2005

High Performance of Rh(Phebox) Catalysts in Asymmetric Reductive Aldol Reaction: High Anti-Selectivity

Hisao Nishiyama,* Takushi Shiomi, Yasunori Tsuchiya, and Isamu Matsuda

Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan

hnishi@apchem.nagoya-u.ac.jp

Received February 2, 2005

Abstract:

Chiral rhodium(bisoxazolinylphenyl) complexes (1 mol %) efficiently catalyze the asymmetric reductive aldol reaction of aldehydes and ,-unsaturated esters at 50 C for ca. 0.5-1.0 h with several hydrosilanes to give the corresponding -hydroxypropionates with extremely high anti-selectivity (up to 98%) and enantioselectivity (up to 96% ee). The stereochemical outcome is likely due to a chairlike cyclic transition state involving rhodium-(E)-enolate.

Download the full text: PDF | HTML