Remote C(sp3)-H heteroarylation of N-fluorocarboxamides with quinoxalin-2(1H)-ones under visible-light-induced photocatalyst-free conditions

We report, for the first time, a visible-light-promoted remote benzylic/aliphatic C(sp(3))-H heteroarylation of N-fluorocarboxamides with quinoxalin-2(1H)-ones. This transformation involves a sequence of amidyl radical generation, 1,5-hydrogen atom transfer (HAT), and cross-dehydrogenative coupling steps. By applying this new method, a broad range of biologically important 3-alkylated quinoxalin-2(1H)-ones (>60 examples) can be readily prepared at room temperature, thus showing the wide utility of this protocol. Notably, this practical reaction occurs under metal- and external photocatalyst-free conditions and exhibits a broad substrate scope, good functional group tolerance, and high chemoselectivity and regioselectivity.

Automated summary

A visible-light-promoted remote benzylic/aliphatic C(sp(3))-H heteroarylation of N-fluorocarboxamides with quinoxalin-2(1H)-ones is reported for the first time. This transformation allows the synthesis of a wide range of biologically important 3-alkylated quinoxalin-2(1H)-ones under metal- and external photocatalyst-free conditions. The method shows good substrate scope, functional group tolerance, chemoselectivity, and regioselectivity.