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 [Au1Cu14(TBBT)12(PPh3)6]+ (TBBTH: p-tert-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.