title: Chemoselective activation of sp(3) vs sp(2) C-H bonds with Pd(II).
abstract: The first selective coupling of a carbon nucleophile with methyl, ethyl, propyl, and butyl arenes in the absence of a directing group is described. Pd(OAc)2 double C-H activation displays remarkable selectivity for the terminal methyl sites in alkyl arenes, rather than the more commonly observed arene sp(2) C-H activation. Mechanistic studies indicate the intermediacy of an azlactone dimer, obtained from oxidation with Pd(OAc)2, and are consistent with a Pd-catalyzed C-H activation vs a radical process. The observed reactivity establishes that typical reaction solvents (e.g., toluene) can readily participate in C-H activation chemistry.
authors.affiliation: Department of Chemistry and Penn Merck High Throughput Experimentation Laboratory, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: John M
authors.initials: JM
authors.lastname: Curto
authors.forename: Marisa C
authors.initials: MC
authors.lastname: Kozlowski
mesh_terms: D000085:Acetates / Q000737:chemistry*; D002384:Catalysis; D007783:Lactones / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*
chemical_list: D000085:Acetates; D007783:Lactones; D009942:Organometallic Compounds; C516071:palladium(II) acetate