π-Coordinating Chiral Primary Amine/Palladium Synergistic Catalysis for Asymmetric Allylic Alkylation

We report an arene-containing chiral primary amine as a dual aminocatalyst and ligand: the pi-coordinating aminocatalyst/palladium synergistic catalysis for asymmetric allylic alkylation of alpha-branched beta-ketocarbonyls. The use of arene-containing chiral primary amine catalyst led to not only enhanced reaction rate but also reversed chiral induction compared with its sterically bulky derivative. Both enantiomers of the allylic adducts bearing acyclic all-carbon quaternary stereocenters could be obtained from the same configured chiral aminocatalysts with high efficiency and excellent regio-, stereo-, and enantioselectivity. Mechanistic studies revealed a distinctive Pd-arene pi-coordination mode for effective catalysis. The pi-coordinating chiral primary amine catalyst could be successfully applied in the asymmetric allylation reactions of vinylethylene carbonates, vinyl epoxides, or simple allylic alcohols.