Stereogenic-at-Metal Zn- and Al-Based N-Heterocyclic Carbene (NHC) Complexes as Bifunctional Catalysts in Cu-Free Enantioselective Allylic Alkylations

Investigations detailed herein demonstrate the ability of chiral bidentate N-heterocyclic carbenes to promote directlywithout the need for a Cu saltsite- and enantioselective C−C bond forming reactions. Within this context, catalytic allylic alkylations of various allylic phosphates with dialkylzinc and trialkylaluminum reagents, performed with chiral bidentate imidazolinium salts and in the absence of a Cu salt, are described. The Cu-free transformations deliver products bearing tertiary or (all-carbon) quaternary stereogenic centers with exceptional site- (>98: