title: Mono-Oxidation of Bidentate Bis-phosphines in Catalyst Activation: Kinetic and Mechanistic Studies of a Pd/Xantphos-Catalyzed C-H Functionalization.
abstract: Kinetic, spectroscopic, crystallographic, and computational studies probing a Pd-catalyzed C-H arylation reaction reveal that mono-oxidation of the bis-phosphine ligand is critical for the formation of the active catalyst. The bis-phosphine mono-oxide is shown to be a hemilabile, bidentate ligand for palladium. Isolation of the oxidative addition adduct, with structural elucidation by X-ray analysis, showed that the mono-oxide was catalytically competent, giving the same reaction rate in the productive reaction as the Pd(II)/xantphos precursor. A dual role for the carboxylate base in both catalyst activation and reaction turnover was demonstrated, along with the inhibiting effect of excess phosphine ligand. The generality of the role of phosphine mono-oxide complexes in Pd-catalyzed coupling processes is discussed.
authors.affiliation: Department of Chemistry, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States ;
authors.forename: Yining
authors.initials: Y
authors.lastname: Ji
authors.affiliation: Department of Chemistry, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States ;
authors.forename: R Erik
authors.initials: RE
authors.lastname: Plata
authors.affiliation: Chemical Development, Bristol-Myers Squibb , One Squibb Drive, New Brunswick, New Jersey 08903, United States.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Regens
authors.affiliation: Chemical Development, Bristol-Myers Squibb , One Squibb Drive, New Brunswick, New Jersey 08903, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Hay
authors.affiliation: Chemical Development, Bristol-Myers Squibb , One Squibb Drive, New Brunswick, New Jersey 08903, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Schmidt
authors.affiliation: Chemical Development, Bristol-Myers Squibb , One Squibb Drive, New Brunswick, New Jersey 08903, United States.
authors.forename: Thomas
authors.initials: T
authors.lastname: Razler
authors.affiliation: Chemical Development, Bristol-Myers Squibb , One Squibb Drive, New Brunswick, New Jersey 08903, United States.
authors.forename: Yuping
authors.initials: Y
authors.lastname: Qiu
authors.affiliation: Chemical Development, Bristol-Myers Squibb , One Squibb Drive, New Brunswick, New Jersey 08903, United States.
authors.forename: Peng
authors.initials: P
authors.lastname: Geng
authors.affiliation: Chemical Development, Bristol-Myers Squibb , One Squibb Drive, New Brunswick, New Jersey 08903, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Hsiao
authors.affiliation: Chemical Development, Bristol-Myers Squibb , One Squibb Drive, New Brunswick, New Jersey 08903, United States.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Rosner
authors.affiliation: Chemical Development, Bristol-Myers Squibb , One Squibb Drive, New Brunswick, New Jersey 08903, United States.
authors.forename: Martin D
authors.initials: MD
authors.lastname: Eastgate
authors.affiliation: Department of Chemistry, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States ;
authors.forename: Donna G
authors.initials: DG
authors.lastname: Blackmond
mesh_terms: D002384:Catalysis; D018360:Crystallography, X-Ray; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*; D010720:Phosphines / Q000737:chemistry*; D014966:Xanthenes / Q000737:chemistry*
chemical_list: D010720:Phosphines; D014966:Xanthenes; D010165:Palladium; C519861:xantphos