Pd-Catalyzed Aerobic Oxidative Coupling of Thiophenes: Synergistic Benefits of Phenanthroline Dione and a Cu Cocatalyst.

ABSTRACT: Substituted bithiophenes are prominent fragments in functional organic materials, and they are ideally prepared via direct oxidative C-H/C-H coupling. Here, we report a novel Pd^II catalyst system, employing 1,10-phenanthroline-5,6-dione (phd) as the ancillary ligand, that enables aerobic oxidative homocoupling of 2-bromothiophenes and other related heterocycles. These observations represent the first use of phd to support Pd-catalyzed aerobic oxidation. The reaction also benefits from a Cu(OAc)₂ cocatalyst, and mechanistic studies show that Cu promotes C-C coupling, implicating a role for Cu^II different from its conventional contribution to reoxidation of the Pd catalyst.

SUBMITTER: Tereniak SJ 

PROVIDER: S-EPMC8099933 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature