Chiral Phosphoric\nAcid-Catalyzed Enantioselective\nSynthesis of 2,2-Disubstituted 2,3-Dihydro-4-quinolones from Isatins\nand 2′-Aminoacetophenones

Herein, we present the enantioselective\nsynthesis of 2,3-dihydro-4-quinolones\nbearing chiral tetrasubstituted carbons from isatins and 2′-aminoacetophenones.\nThe transformation is mediated by a chiral phosphoric acid catalyst\nand proceeds via an <i>in situ</i> generated ketimine and\nsubsequent enantioselective intramolecular cyclization. The methodology\nfeatures a broad scope and functional group tolerance with yields\nand enantioselectivities of up to 99% and 98% ee. Detailed density\nfunctional theory (DFT) calculations support the proposed reaction\nmechanism and the origin of asymmetric induction.