Catalytic enantioselective silylation of N-sulfonylimines: asymmetric synthesis of α-amino acids from CO2 via stereospecific carboxylation of α-amino silanes.Org Lett. 2014 Jun 06; 16(11):3028-31.OL
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-amino acids in a stereoretentive manner. This two-step sequence provides a new synthetic protocol for optically active α-amino acids from gaseous CO2 and imines in the presence of a catalytic amount of a chiral source.