Chiral Ag-Complex Catalyzed Enantioselective α-Functionalization of Cyclic Azomethine Ylides with Concomitant Remote-Controlled Asymmetric Desymmetrization of N-Arylmaleimides and Cyclopentene-1,3-diones

Abstract

The asymmetric cycloaddition reactions of 1,3-fused cyclic azomethine ylides have been extensively studied, but the non-cyclic α-functionalization of these compounds remains unexplored. Herein, an efficient combination of the catalytic enantioselective non-cyclic α-functionalization of 1,3-fused cyclic azomethine ylides and the remote-controlled asymmetric desymmetrization of N-arylmaleimides and cyclopentene-1,3-diones has been achieved with a catalyst system consisting of a chiral P,N-ferrocene ligand and AgNO₂. This reaction allowed for the synthesis of a series of enantioenriched 3,4-dihydroisoquinoline derivatives bearing multiple stereogenic elements/centers with good yields and stereoselectivities. The practicality of this method was demonstrated by gram-scale synthesis and derivatizations of the products.