Atomically Precise Metal Nanoclusters as Single Electron Transferers for Hydroborylation.

The emergence of metal nanoclusters with atomically precise compositions and structures provides an opportunity for in-depth investigation of catalysis mechanisms and structure-property correlations at the nanoscale. However, a serious problem for metal nanocluster catalysts is that the ligands inhibit the catalytic activity through deactivating the surface of the nanoclusters. Here, we introduce a novel catalytic mode for metal nanoclusters, in which the nanoclusters initiate the catalysis via single electron transfer (SET) without destroying the integrity of nanoclusters, providing a solution for the contradiction between activity and stability of metal nanoclusters. We illustrated that the novel activation mode featured low catalyst loading (0.01 mol %), high TOF, mild reaction conditions, and easy recycling of catalyst in alkyne hydroborylation, which often suffered from poor selectivity, low functional group tolerance, etc. Furthermore, the catalyst [AuCu(TBBT)(PPh)] (TBBTH: --butylthiophenol) can be applied in highly efficient tandem processes such as hydroborylation-deuteration and hydroborylation-isomerization, demonstrating the utility of the introduced activation mode for metal nanoclusters.