Asymmetric organocatalytic tandem cyclization/transfer hydrogenation: A synthetic strategy for enantioenriched nitrogen heterocycles

An asymmetric organocatalytic tandem reaction comprising cyclization/transfer hydrogenation has been established in a compatible and synergistic way, leading to the step-economical synthesis of enantioenriched tetrahydroquinoxalines and dihydroquinoxalinones from readily accessible materials in excellent enantioselectivity of up to >99% ee. This protocol of a one-operation tandem reaction combines the merits of both tandem reactions and asymmetric organocatalysis, providing an efficient strategy for concisely and enantioselectively synthesizing nitrogen heterocycles with biological relevance.