Catalytic Asymmetric Passerini-Type Reaction: Chiral Aluminum−Organophosphate-Catalyzed Enantioselective α-Addition of Isocyanides to Aldehydes

A chiral Lewis acid catalyst was prepared by mixing 2 equiv of chiral binol-derived organophosphoric acid and 1 equiv of Et₂AlCl. In the presence of a catalytic amount of [4j]₂Al(III)Cl complex (0.05 equiv), reaction between α-isocyanoacetamides (2) and aldehydes (3) afforded the corresponding 5-aminooxazoles (1) in good yields and enantioselectivities. Complex [4j]₂Al(III)Cl isolated as a white solid displayed similar reactivity as that prepared in situ.