Synthesis of 2-Fluorobenzofuran by Photocatalytic Defluorinative Coupling and 5<i>-endo-trig</i> Cyclization
Xiaoli He, Jiahao Ling, Zhixing Fang, Lei Zhou
Abstract
An alkyl radical-triggered dual C–F bond cleavage of α-CF 3 - ortho -hydroxystyrenes for the synthesis of 2-fluorobenzofurans was developed. The visible-light-induced defluorinative cross-coupling reactions of α-CF 3 - ortho -hydroxystyrenes with a variety of carboxylic acids produced gem -difluoroalkenes, which underwent S N V-type 5 -endo-trig cyclization to give 2-fluorobenzofurans. Mechanistic studies indicated that the electron transfer between phenoxyl radicals and carboxylates was the major pathway for the generation of alkyl radicals.
Topics & Concepts
ChemistryRadicalPhotocatalysisAlkylBond cleavageCleavage (geology)PhotochemistryElectron transferStereochemistryMedicinal chemistryOrganic chemistryCatalysisEngineeringGeotechnical engineeringFracture (geology)Fluorine in Organic ChemistryRadical Photochemical ReactionsInorganic Fluorides and Related Compounds