Significant counterion effect of the In(III)–pybox complex in highly enantioselective carbonyl-ene reactions of ethyl glyoxylate

A highly efficient enantioselective carbonyl-ene reaction of ethyl glyoxylate catalyzed by an In(III)–pybox complex, which is designed based on the counterion effect, is reported. Reactions of both aliphatic and aromatic 1,1-disubstituted olefins proceed smoothly to give enantioenriched homoallylic alcohols with excellent yields and enantioselectivities. In addition, electron-withdrawing as well as donating groups on the phenyl ring of α-methyl styrenes are tolerated in this reaction.