Visible-light-induced annulation of 4-aminocoumarins to tetrahydropyrimidine-fused coumarins and evaluation of their antitumor activities

Abstract

A green and efficient synthetic route to novel tetrahydropyrimidine-fused coumarins has been established via a visible-light-induced multicomponent reaction. This additive- and exogenous photocatalyst-free strategy employs 4-aminocoumarins, N-arylglycines, and formaldehyde as readily available feedstocks, proceeding under mild conditions with high atom economy. The protocol features broad substrate scope, excellent functional group compatibility, high yields and facile scalability. Furthermore, the synthesized compounds exhibit promising biological activities in preliminary assays.