Catalytic Enantioselective Silylation of<i>N</i>-Sulfonylimines: Asymmetric Synthesis of α-Amino Acids from CO<sub>2</sub>via Stereospecific Carboxylation of α-Amino Silanes
作者:Tsuyoshi Mita、Masumi Sugawara、Keisuke Saito、Yoshihiro Sato
DOI:10.1021/ol501143c
日期:2014.6.6
A catalytic enantioselective silylation of N-tert-butylsulfonylimines using a Cu–secondary diamine complex was demonstrated. The resulting optically active α-amino silanes could be carboxylated under a CO2 atmosphere (1 atm) to afford the corresponding α-aminoacids in a stereoretentive manner. This two-step sequence provides a new synthetic protocol for optically active α-aminoacids from gaseous
Stereoretentive Addition of<i>N</i>-<i>tert</i>-Butylsulfonyl-α-Amido Silanes to Aldehydes, Ketones, α,β-Unsaturated Esters, and Imines
作者:Tsuyoshi Mita、Keisuke Saito、Masumi Sugawara、Yoshihiro Sato
DOI:10.1002/asia.201600270
日期:2016.5.20
Enantioenriched N‐tert‐butylsulfonyl‐α‐amido silanes were successfully reacted with aldehydes, ketones, imines, and α,β‐unsaturated esters in the presence of a sub‐stoichiometric amount of CsF (0.5 equiv) in 1,2‐dimethoxyethane (DME) at −20 °C to afford the corresponding coupling products with up to 89 % enantiospecificity in a retentive manner.