Anaerobic photoinduced Cu(0/I)-mediated Glaser coupling in a radical pathway.

ABSTRACT: The reaction mechanism of the historic copper-catalyzed Glaser coupling has been debated to be based on redox cycles of Cu ions in specific oxidation states or on a radical mechanism based on Cu(0)/Cu(I). Here, the authors demonstrate two coexisting Glaser coupling pathways which can be differentiated by anaerobic/irradiation or aerobic reaction conditions. Without O₂, copper(I) acetylides undergo a photo-excited pathway to generate highly reactive alkynyl radicals, which combine together to form a homo-coupling product or individually react with diverse X-H (X = C, N, O, S and P) substrates via hydrogen atom transfer. With O₂, copper(I) acetylides are oxidized to become a Cu-acetylide/Cu-O merged Cu(I/II) intermediate for further oxidative coupling. This work not onl

SUBMITTER: Zhang S 

PROVIDER: S-EPMC10598264 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature