Highly selective visible-light-induced cascade cyclization of vinyl sulfoxonium ylides with azides: a novel synthetic approach towards trisubstituted furans†

A simple protocol for the synthesis of trisubstituted furans via visible-light-driven regioselective cascade cyclization of vinyl sulfoxonium ylides with azides has been achieved. The reaction proceeds through the formation of a novel α-enone-α′-amide sulfoxonium ylide, which undergoes cyclization upon blue light irradiation to yield a trisubstituted furan scaffold. This method offers advantages including the absence of transition metals and photocatalysts, and the desired trisubstituted furans were prepared in good to excellent yields.