Copper Catalyzed One-Pot Three-Component Imination–Alkynylation–aza-Michael Sequence: Enantio- and Diastereoselective Syntheses of 1,3-Disubstituted Isoindolines and Tetrahydroisoquinolines

An enantio- and diastereoselective syntheses of 1, 3-disubstituted isoindolines and tetrahydroisoquinolines via CuI-Pybox-diPh catalyzed one-pot imination–alkynylation–aza-Michael sequence has been reported. The three-component reaction produces one C–C and two C–N bonds sequentially with high yield (up to 92%), enantioselectivity (up to 99%), and diastereoselectivity (up to 9:1) in a single operation. Furthermore, the synthetic utility of the product has been demonstrated by LiAlH4 reduction of ester and hydrogenation of alkyne functionality without losing the stereoselectivity.