Asymmetric cooperative catalysis in a three-component reaction: mechanism and origin of enantio- and diastereoselectivities

Abstract

Mechanistic insights gained through Density functional Theory (DFT M06 and B3LYP) computations on a three-component cooperative asymmetric catalytic reaction between a diazo ester, a carbamate and an imine, catalyzed by dirhodium acetate and chiral phosphoric acid (Bronsted acid), are presented. The addition of the dirhodium-bound enol to the imine yielding an α,β-diamino ester is energetically more preferred over a potentially competitive protonation of the same enol leading to an α-amino ester.