Auto-oxidation-driven vicinal C(sp3)–H desaturative cyclization of tertiary alkylamines for the synthesis of pyrido[3,2-c]coumarins

Abstract

Utilizing the auto-oxidation of tertiary alkylamines and aromatic aldehydes, an unprecedented desaturative cyclization with 4-aminocoumarins has been achieved without the need for additional catalysts or reagents. This vicinal C(sp3)−H cyclization is initiated through aerobic C−H activation, generating α-aminoalkyl hydroperoxides and acyl radicals, subsequently involving radical addition of elusive linear enamines and a [3 + 3] cyclization of 4-aminocoumarins to afford a wide range of highly valuable pyrido[3,2-c]coumarin derivatives.