Oxidant speciation and anionic ligand effects in the gold-catalyzed oxidative coupling of arenes and alkynes.

ABSTRACT: The mechanism of the gold-catalyzed oxidative cross-coupling of arenes and alkynes has been studied in detail combining stoichiometric experiments with putative reaction intermediates and DFT calculations. Our data suggest that ligand exchange between the alkyne, the Au(i)-catalyst and the hypervalent iodine reagent is responsible for the formation of both an Au(i)-acetylide complex and a more reactive "non-symmetric" I(iii) oxidant responsible for the crucial Au(i)/Au(iii) turnover. Further, the reactivity of the in situ generated Au(iii)-acetylide complex is governed by the nature of the anionic ligands transferred by the I(iii) oxidant: while halogen ligands remain unreactive, acetato ligands are efficiently displaced by the arene to yield the observed Csp²-Csp cross-c

SUBMITTER: Hofer M 

PROVIDER: S-EPMC6844217 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature