Catalytic asymmetric Passerini-type reaction: chiral aluminum-organophosphate-catalyzed enantioselective alpha-addition of isocyanides to aldehydes.J Org Chem. 2009 Nov 06; 74(21):8396-9.JO
A chiral Lewis acid catalyst was prepared by mixing 2 equiv of chiral binol-derived organophosphoric acid and 1 equiv of Et(2)AlCl. In the presence of a catalytic amount of [4j](2)Al(III)Cl complex (0.05 equiv), reaction between alpha-isocyanoacetamides (2) and aldehydes (3) afforded the corresponding 5-aminooxazoles (1) in good yields and enantioselectivities. Complex [4j](2)Al(III)Cl isolated as a white solid displayed similar reactivity as that prepared in situ.