Au(III) catalyzes the cross-coupling between activated methylenes and alkene derivatives

Abstract

© 2020 Elsevier Inc. In the last decade substantial efforts were devoted towards the exploitation of the Au(I) as a promising tool to promote C[sbnd]C bond formation reactions via the activation of unsaturations. Among these efforts, Au(I)/Au(III) cross couplings mediated by a co-oxidant or by photoactivation sit at a privileged position. Au(III) has also shown a rich chemistry but, due to its hardness and lower affinity for unsaturations, it is less often the catalyst of choice in C[sbnd]C bond forming strategies. Surprisingly, we have recently found two examples of cross-coupling reactions in which the authors report to be adding Au(III) to the reaction flask while claiming that Au(I) is the species responsible for the catalytic events. One of such cases even occurs under oxidizing conditions. Here we present a detailed computational study in which we explore the mechanism behind these C[sbnd]C forming reactions. Our results suggest that Au(III) can efficiently catalyze these transformations, thus invoking this exotic reduction is not only unnecessary but also energetically unfavourable.