Catalytic C–O Cross Coupling by Kinetically Stabilized, Catenane-Coordinated Copper Complexes

Abstract

Ligand design is fundamental to transition-metal catalyst development, and strategies such as varying the coordination donors and optimizing structural parameters of the ligand covalent framework are common directions in the search of better catalysts. Inspired by the high efficiency of metalloenzymes in which active metal sites are supported by peptide ligands, we propose that effective transition-metal catalysts could also be obtained by the use of mechanically bonded ligands that provide a shielded but assessable, kinetically stabilized metal center. In this talk, a new C–O cross coupling of bromodicarbonyl and phenol that is catalyzed by catenane-supported copper(I) complexes will be discussed. Flexibility of the mechanical bond in the catenane ligand not only provides a responsive copper coordination for substrate transformation, but also allows the facile regeneration of the stable, coordinative saturated copper in the resting state. The catenane-supported copper catalyst is stable and the catalysis can be performed under air in high efficiency with a broad substrate scope.