l-Amino acid ester as a biomimetic reducing agent for the reduction of unsaturated CC bonds

Abstract

The first example of an efficient protocol for the reduction of disubstituted methyleneindolinones, isoindigos and tetrasubstituted olefins for the synthesis of 3-substituted 2-oxindoles, dihydroisoindigos and tetrasubstituted ethane derivatives using an L-amino acid ester as an attractive biomimetic reducing agent has been developed. This new protocol has the advantages of mild reaction conditions without the need for any metal catalysts, a broad substrate scope (31 examples), excellent yields (90–98%) and good functional group tolerance, providing an operationally simple and practically useful methodology for reductive reactions. The L-amino acid derivative, which is cheap, nontoxic and easy to handle, serves as a new biomimetic reducing agent for use in organic chemistry, providing a novel and promising approach for future applications in reductive reactions.