title: Oxidative palladium(II) catalysis: A highly efficient and chemoselective cross-coupling method for carbon-carbon bond formation under base-free and nitrogenous-ligand conditions.
abstract: We report herein the development of a general and mild protocol of oxygen-promoted Pd(II) catalysis resulting in the selective cross-couplings of alkenyl- and arylboron compounds with various olefins. Unlike most cross-coupling reactions, this new methodology works well even in the absence of bases, consequently averting undesired homo-couplings. Nitrogen-based ligands including dimethyl-phenanathroline enhance reactivities and offer a highly efficient and stereoselective methodology to overcome challenging substrate limitations. For instance, oxidative palladium(II) catalysis is effective with highly substituted alkenes and cyclic alkenes, which are known to be incompatible with other known catalytic conditions. Most examined reactions progressed smoothly to completion at low temperatures and in short times. These interesting results provide mechanistic insights and utilities for a new paradigm of palladium catalytic cycles without bases.
authors.affiliation: Loker Hydrocarbon Research Institute and Department of Chemistry, University of Southern California, Los Angeles, California 90089-1661, USA.
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Yoo
authors.forename: Cheol Hwan
authors.initials: CH
authors.lastname: Yoon
authors.forename: Rajesh K
authors.initials: RK
authors.lastname: Mishra
authors.forename: Young Chun
authors.initials: YC
authors.lastname: Jung
authors.forename: Sung Wook
authors.initials: SW
authors.lastname: Yi
authors.forename: Kyung Woon
authors.initials: KW
authors.lastname: Jung
mesh_terms: D000475:Alkenes / Q000737:chemistry; D001895:Boron / Q000737:chemistry; D001897:Boronic Acids / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D003432:Cross-Linking Reagents / Q000737:chemistry*; D003512:Cyclohexanones / Q000737:chemistry; D004951:Esterification; D008024:Ligands; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*; D012997:Solvents; D013696:Temperature
chemical_list: D000475:Alkenes; D001897:Boronic Acids; D003432:Cross-Linking Reagents; D003512:Cyclohexanones; D008024:Ligands; D012997:Solvents; C036468:cyclohexanone; D010165:Palladium; D002244:Carbon; D009584:Nitrogen; D001895:Boron