Photocatalytic transformation of aliphatic heterocycles and electron-poor alkenes into functionalized heteroarenes

Abstract

We hereby describe the synthesis of functionalized heteroarenes (furans, pyrroles, thiophenes and indoles) thanks to the combination between tetrabutylammonium decatungstate (TBADT) photocatalysis and cobaloxime catalysis. The protocol makes use of aliphatic heterocycles and electron-poor alkenes, that are efficiently converted to the final products through a functionalization/aromatization sequence. Dedicated kinetic and deuteration studies allowed rationalization of the reaction mechanism. Overall, the process is characterized by a high atom economy, with hydrogen gas as the only coupled product.