Visible-Light Copper Nanocluster Catalysis for the C–N Coupling of Aryl Chlorides at Room Temperature
Arunachalam Sagadevan, Atanu Ghosh, Partha Maity, Omar F. Mohammed, Osman M. Bakr, Magnus Rueping
Abstract
Activation of aryl chlorides in cross-coupling reactions is a long-standing challenge in organic synthesis that is of great interest to industry. Ultrasmall (<3 nm), atomically precise nanoclusters (NCs) are considered one of the most promising catalysts due to their high surface area and unsaturated active sites. Herein, we introduce a copper nanocluster-based catalyst, [Cu61(StBu)26S6Cl6H14] (Cu61NC) that enables C–N bond-forming reactions of aryl chlorides under visible-light irradiation at room temperature. A range of N-heterocyclic nucleophiles and electronically and sterically diverse aryl/hetero chlorides react in this new Cu61NC-catalyzed process to afford the C–N coupling products in good yields. Mechanistic studies indicate that a single-electron-transfer (SET) process between the photoexcited Cu61NC complex and aryl halide enables the C–N-arylation reaction.