Catalytic, asymmetric Mannich-type reactions of alpha-imino esters bearing readily removable substituents on nitrogen.
[reaction: see text] Catalytic, enantioselective Mannich-type reactions of alpha-imino esters bearing readily removable substituents on nitrogen are described. Several N-carbamate-protected alpha-imino esters, which are readily prepared from 2-bromoglycine esters using a polymer-supported amine, reacted with silicon enolates to afford the desired adducts in high yields with high enantioselectivity using a copper(II)-diamine complex. Easy deprotection of the product amine and transformation to free alpha-amino acid derivatives have also been demonstrated.
Nakamura
Yoshitaka
Y
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Matsubara
Ryosuke
R
Kiyohara
Hiroshi
H
Kobayashi
Shū
S