Visible light-mediated gold-catalyzed alkynylative cyclization of allenoates with iodoalkynes for the synthesis of β-alkynyl-γ-butenolides

A method for the tandem cyclization/alkynylation of allenoates with iodoalkynes via gold catalysis under light irradiation is described. Mechanistic studies support that an energy-transfer event takes place, rather than a redox pathway.