title: Decarboxylative-coupling of allyl acetate catalyzed by group 10 organometallics, [(phen)M(CH3)]+.
abstract: Gas-phase carbon-carbon bond forming reactions, catalyzed by group 10 metal acetate cations [(phen)M(O2CCH3)](+) (where M = Ni, Pd or Pt) formed via electrospray ionization of metal acetate complexes [(phen)M(O2CCH3)2], were examined using an ion trap mass spectrometer and density functional theory (DFT) calculations. In step 1 of the catalytic cycle, collision induced dissociation (CID) of [(phen)M(O2CCH3)](+) yields the organometallic complex, [(phen)M(CH3)](+), via decarboxylation. [(phen)M(CH3)](+) reacts with allyl acetate via three competing reactions, with reactivity orders (% reaction efficiencies) established via kinetic modeling. In step 2a, allylic alkylation occurs to give 1-butene and reform metal acetate, [(phen)M(O2CCH3)](+), with Ni (36%) > Pd (28%) > Pt (2%). Adduct formation, [(phen)M(C6H11O2)](+), occurs with Pt (24%) > Pd (21%) > Ni(11%). The major losses upon CID on the adduct, [(phen)M(C6H11O2)](+), are 1-butene for M = Ni and Pd and methane for Pt. Loss of methane only occurs for Pt (10%) to give [(phen)Pt(C5H7O2)](+). The sequences of steps 1 and 2a close a catalytic cycle for decarboxylative carbon-carbon bond coupling. DFT calculations suggest that carbon-carbon bond formation occurs via alkene insertion as the initial step for all three metals, without involving higher oxidation states for the metal centers.
authors.affiliation: School of Chemistry, ‡Bio21 Institute of Molecular Science and Biotechnology, and §ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, The University of Melbourne , Melbourne, Victoria 3010, Australia.
authors.forename: Matthew
authors.initials: M
authors.lastname: Woolley
authors.forename: Alireza
authors.initials: A
authors.lastname: Ariafard
authors.forename: George N
authors.initials: GN
authors.lastname: Khairallah
authors.forename: Kim H
authors.initials: KH
authors.lastname: Kwan
authors.forename: Paul S
authors.initials: PS
authors.lastname: Donnelly
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: White
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Canty
authors.forename: Brian F
authors.initials: BF
authors.lastname: Yates
authors.forename: Richard A J
authors.initials: RA
authors.lastname: O'Hair
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000498:Allyl Compounds / Q000737:chemistry*; D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry*; D003653:Decarboxylation; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry; D011789:Quantum Theory
chemical_list: D000085:Acetates; D000498:Allyl Compounds; D056831:Coordination Complexes; D010165:Palladium; D009532:Nickel; C498551:allyl acetate