A TBADT photocatalyst-enabled radical-induced cyclization pathway to access functionalized dihydrobenzofurans.

Herein, this work describes a photoinduced visible light-mediated radical cyclization for constructing dihydrobenzofuran (DHB) scaffolds. Notably, this cascade photochemical process is tolerable with various aromatic aldehydes and diverse alkynyl aryl ethers and proceeds an intramolecular 1,5-hydrogen atom transfer (HAT) pathway. Significantly, acyl C-H activation under mild conditions has been achieved without the use of additives or reagents. The photocatalyst, tetrabutylammonium decatungstate (TBADT), plays an important role in the present strategy by facilitating the well-known hydrogen atom transfer during the course of the reaction.