Chiral Counteranions in Asymmetric Transition-Metal Catalysis:  Highly Enantioselective Pd/Brønsted Acid-Catalyzed Direct α-Allylation of Aldehydes

We have developed a highly enantioselective Pd/chiral acid-catalyzed α-allylation of α-branched aldehydes with an allyl amine as the allylating species that creates all-carbon quaternary stereogenic centers in high yields and enantioselectivities. To our knowledge, this is the first time that a chiral anionic ligand is applied for achieving asymmetric induction in a palladium-catalyzed allylic alkylation reaction.