Highly enantioselective ketone-ene reactions of trifluoropyruvate: significant counterion effect of the In(III)-pybox complex.

A chiral indium(III)-pybox complex catalyzed asymmetric ketone-ene reaction of trifluoropyruvate is described. Both aromatic and aliphatic 1,1-disubstituted alkenes reacted smoothly to give the enantioenriched tertiary homoallylic alcohols in good to excellent yields (up to 99%) and with excellent enantioselectivities (up to 98% ee).