Photocatalytic decarboxylative alkylations of C(sp3)-H and C(sp2)-H bonds enabled by ammonium iodide in amide solvent

Abstract

A simple ammonium iodide salt in amide solvent catalyzes regioselective decarboxylative alkylation of C(sp3)-H bonds of N-aryl glycine derivatives, of C(sp2)-H bond of heteroarenes, and cascade radical addition to unsaturated bond followed by intramolecular addition to arene, with a broad scope of N-hydroxyphthalimide derived redox active esters under visible light irradiation. The reactions are suggested to proceed through photoactivation of a transiently assembled chromophore from electron-deficient phthalimide moiety and iodide anion through an anion-π interaction in solvent cage followed by diffusion to generate solvated free radical species to react with C-H substrates The simplicity, practicality, and broad substrate scope of this method highlight the synthetic power of photocatalysis through transiently assembled chromophore, and will hopefully inspire further developments of low cost photocatalysis based on various non-covalent interactions, which are prevalent in supramolecular chemistry and biosystems, for sustainable organic synthesis.