Formation of 3-Alkynylidenephthalides by Gold(I)-Catalyzed Alkynylative Cyclization of <i>o</i>-Alkynylbenzoic Acids under Visible Light Irradiation
María Ballarín‐Marión, Jorge C. Herrera‐Luna, Vincent Corcé, Héloïse Dossmann, Cyril Ollivier, Virginie Mouriès‐Mansuy, Louis Fensterbank
Abstract
Herein, we report a Csp 2 –Csp cross-coupling process involving the merger of gold catalysis and visible light photocatalysis leading to the alkynylative cyclization of o -alkynyl benzoic acids. The corresponding and previously undescribed alkynylidenephthalide products were obtained as mixtures of E: Z isomers. The key C–C bond formation is based on the photoactivation of the oxidative addition of an alkynyliodide to a vinylgold(I) intermediate resulting from an initial 5- exo -dig cyclization pathway, as supported by mechanistic studies including DFT calculations.
Topics & Concepts
IrradiationCatalysisVisible spectrumChemistryPhotochemistryMaterials scienceOrganic chemistryPhysicsOptoelectronicsNuclear physicsCatalytic Alkyne ReactionsOxidative Organic Chemistry ReactionsCatalytic C–H Functionalization Methods