One-pot gram-scale synthesis of robust copper nanoclusters for photocatalytic difluoroalkylarylation of alkenes

Atomically precise copper nanoclusters have emerged as a promising class of catalysts for driving chemical reactions. However, the exploration of copper nanocluster catalysts has been slow, likely due to their complex synthetic process, limited stability, and low activity under mild conditions. In this study, we present a highly stable copper nanocluster [Cu₈(S₂CN(CH₃)₂)₆(PPh₃)₄]²⁺ (where S₂CN(CH₃)₂ is dimethyldithiocarbamate and PPh₃ is triphenylphosphine) that exhibits a facile synthetic protocol and high photocatalytic performance. The cluster can be easily obtained by reducing Cu(S₂CN(CH₃)₂)₂ with (PPh₃)₂CuBH₄ in the presence of 3,5-bis(trifluoromethyl)pyrazole in a one-pot reaction, even yielding gram-scale product through a one-step process. A comprehensive experimental and theoretical characterization of the cluster provides a deep understanding of its atomic and electronic structure, which also explains its high stability under irradiation treatment. Importantly, the cluster enables the photo-catalytic difluoroalkylarylation of alkenes at room temperature, resulting in a wide range of complex difluoromethyl compounds under mild conditions. This study not only presents an efficient synthetic strategy for accessing copper nanoclusters with atomically precise and highly robust structures, but also highlights the potential of atomically precise copper nanocluster catalysts in rapidly constructing molecular complexity with high material economy.