title: A detailed study of acetate-assisted C-H activation at palladium(IV) centers.
abstract: This report describes a detailed investigation of acetate-assisted C-H activation at Pd(IV) centers supported by the tris(2-pyridyl)methane (Py3CH) ligand. Mechanistic information about this transformation has been obtained through the following: (i) extensive one- and two-dimensional NMR analysis, (ii) reactivity studies of a series of substituted analogues, and (iii) isotope effect studies. These experiments all suggest that C-H activation at [(Py3CH)Pd(IV)(biphenyl)Cl2](+) occurs via a multistep process involving chloride-to-acetate ligand exchange followed by conformational and configurational isomerization and then C-H cleavage. The data also suggest that C-H cleavage proceeds via an acetate-assisted mechanism with the carboxylate likely serving as an intramolecular base. The viability of acetate-assisted C-H activation at high valent palladium has important implications for the design and optimization of catalytic processes involving this transformation as a key step.
authors.affiliation: Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA.
authors.forename: Ansis
authors.initials: A
authors.lastname: Maleckis
authors.forename: Jeff W
authors.initials: JW
authors.lastname: Kampf
authors.forename: Melanie S
authors.initials: MS
authors.lastname: Sanford
mesh_terms: D000085:Acetates / Q000737:chemistry*; D007202:Indicators and Reagents; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D010165:Palladium / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D014961:X-Ray Diffraction
chemical_list: D000085:Acetates; D007202:Indicators and Reagents; D008024:Ligands; D010165:Palladium