Chemodivergent Photocatalytic Synthesis of Dihydrofurans and β,γ-Unsaturated Ketones

A synthetic procedure, catalysed by Ir(ppy)3 under visible-light irradiation, for the chemodivergent synthesis of 2,3-dihydrofurans (3) or β,γ-unsaturated ketones (7) starting from α-halo ketones (1) and alkenes (2) has been developed. The mild reaction conditions and the redox-neutral nature of the process make it particularly sustainable avoiding the use of both sacrificial reactants and stoichiometric strong oxidants. Careful experimental investigations, supported by DFT calculations, allowed to disclose in details a possible mechanistic pathway and to direct the synthesis chemodivergently either toward 3 or 7, depending not only on the nature of the substrates, but also on the choice of the experimental conditions. (Figure presented.).