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

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-<i>c</i>]coumarin derivatives.