Ni(CO)2(PPh3)2 as a Bench-Stable Ni(0) Source for Ni/NHC-Catalyzed C–N Cross-Coupling Reactions

Commercially available air stable Ni(CO)2(PPh3)2 was found to be an efficient air-tolerant nickel source - an alternative to the commonly used air sensitive Ni(COD)2 - for the in situ generation of catalytically active Ni(0)/NHC systems in C–N cross coupling reactions. For example, the combination of Ni(CO)2(PPh3)2 with IPr·HCl and sodium tert butoxide provides efficient catalysis of the coupling between aryl chlorides and various amines, affording the corresponding N-arylated products in good to excellent yields. The likely mechanism of catalyst activation involves coordinated CO ligands and leads to arylamide formation.