Unimolecular Reactions of Organocuprates and Organoargentates

Abstract

The gas-phase fragmentation reactions of the group 11 organometallates [CH3MR]− (R = CH3CH2, CH3CH2CH2, (CH3)2CH, (CH3)3C, CH2CHCH2, PhCH2, Ph, M = Cu, Ag) and [CH3CH2CuCH2CH3]− were studied by density functional theory (DFT) calculations and, for those accessible in the gas phase, via collision-induced dissociation (CID) and selected deuterium labeling experiments. The mixed metallates [CH3MR]− were found to fragment via a diverse set of pathways, including bond homolysis, bond heterolysis, and β-hydride elimination. A 1,2-dyotropic rearrangement was observed for R = Ph. DFT calculations suggest that the M−C bond energy, the availability of metal orbitals for π-bonding, and the nature of the ligand R group substituents are the main factors that control the observed reactivity. Comparisons with the known solution-phase reactivity of organocopper and organosilver species are made.