Organocatalytic enantioselective construction of axially chiral (1H)-isochromen-1-imines

Abstract

Heterocycloalkenyl atropisomers, derived from biaryl atropisomers and axially chiral styrenes, have emerged as a new class of nonbiaryl C–C atropisomers due to the benefit in improving the pharmacological activity and structural diversity. This paper proposes an intramolecular annulation strategy for constructing the heterocycloalkenyl atropisomers (1H)-isochromen-1-imines by organocatalysis. Various heterocycloalkenyl atropisomers (1H)-isochromen-1-imines were prepared in good to excellent yields with excellent enantioselectivity (up to 98% ee), and could be easily converted to atropisomeric lactones isocoumarins.