An enantioselective three-component reaction of diazoacetates with indoles and enals by iridium/iminium co-catalysis

The first example of chiral secondary amine and iridium(i) co-catalyzed enantioselective three-component reaction of aryldiazoacetates, indoles and enals was rationally designed and developed to afford 3-substituted indole derivatives in good yields and with moderate diastereoselectivity as well as excellent enantioselectivity. This reaction is proposed to proceed through the enantioselective trapping of iridium(i)-associated zwitterionic intermediates via selective 1,4-addtition to the chiral amine activated enals.