Origin of the different reactivity of the high-valent coinage-metal complexes [RCuiiiMe3]− and [RAgiiiMe3]− (R=allyl)**

Abstract

High-valent tetraalkylcuprates(iii) and -argentates(iii) are key intermediates of copper- and silver-mediated C−C coupling reactions. Here, we investigate the previously reported contrasting reactivity of [RMiiiMe3]− complexes (M=Cu, Ag and R=allyl) with energy-dependent collision-induced dissociation experiments, advanced quantum-chemical calculations and kinetic computations. The gas-phase fragmentation experiments confirmed the preferred formation of the [RCuMe]− anion upon collisional activation of the cuprate(iii) species, consistent with a homo-coupling reaction, whereas the silver analogue primarily yielded [AgMe2]−, consistent with a cross-coupling reaction. For both complexes, densi..