Chiral Bis(NHC)−Palladium(II) Complex Catalyzed and Diethylzinc-Mediated Enantioselective Umpolung Allylation of Aldehydes

Abstract

A series of chiral bis(NHC)−Pd(II) complexes bearing different coordinating counterions have been prepared and successfully applied in Et2Zn-mediated enantioselective umpolung allylation of aldehydes with cyclohexenyl acetate, affording the homoallylic alcohols in moderate to excellent yields (up to 96%), modest enantioselectivities (54%−66% ee), and good to excellent syn diastereoselectivities (up to 99:1 dr).