Asymmetric Synthesis of α-Aryl α-Amino Acids via NHC-Catalyzed Dynamic Kinetic Resolution

Herein, we report a protocol for the asymmetric synthesis of unnatural α-aryl α-amino acids, a structural motif prevalent in numerous pharmaceutically active agents, via an N-heterocyclic carbene (NHC)-catalyzed dynamic kinetic resolution (DKR) process. This method delivers a broad range of chiral α-aryl α-amino acids in good yields, with good functional group tolerance and high enantioselectivities. Further chemical transformations offered access to key precursors of bioactive molecules, as well as important ligands and organocatalysts, without erosion of the enantioselectivity. Density functional theory (DFT) calculations elucidated well the origin of the high level of stereocontrol observed in the NHC-catalyzed DKR process.