A Simple Protocol for the C-N Cross-Coupling of Aryl Chlorides with Amines Applying Ni/NHC Catalysis

An efficient protocol for the C-N cross-coupling of aryl chlorides with (hetero)aryl- and alkyl amines under nickel catalysis has been developed. The main advantage of the protocol is the use of a self-activated Ni/NHC catalytic system generated in situ from readily available bench-stable air-tolerant precursors: NiCl2Py2, IPrHCl, and sodium tert-butoxide. A mass spectrometry mechanistic study of the reaction system revealed the dynamics of competitive processes of Ni/NHC active species formation and degradation involving NHC reductive elimination reactions and tert-butoxide base. Optimization of the NiCl2Py2/IPrHCl/tBuONa ratio and the reaction temperature allowed efficient catalysis to be achieved. The developed simple protocol represents a simple alternative for methods relying on the use of air-sensitive and unstable Ni(cod)2 or expensive well-defined Ni/NHC precatalysts.

Reference: ChemCatChem, 2023, e202300466.

DOI: 10.1002/cctc.202300466.