Iridium-catalyzed [3+2] cyclization of terminal alkynes with sulfoxonium ylides to construct 2,5-disubstituted furans

A novel iridium-catalyzed [3+2] cyclization of sulfoxonium ylides with terminal alkynes for the synthesis of 2,5-disubstituted furans has been demonstrated. This protocol features a broad substrate scope, mild reaction conditions, and good to excellent yields. Mechanistic studies indicate that the reaction may involve the C(sp)-H bond insertion of sulfoxide ylides to generate allenones, followed by cyclization. In addition, late-stage functionalization of complex architectures shows the utility of this method.