Regioselective Direct C–H Bond Heteroarylation of Thiazoles Enabled by an Iminopyridine-Based α-Diimine Nickel(II) Complex Evaluated by DFT Studies

Abstract

Direct C−H bond arylation is a highly effective method for synthesizing arylated heteroaromatics. This method reduces the number of synthetic steps and minimizes the formation of impurities. We report an air-and moisture-stable iminopyridine-based α-diimine nickel(II) complex for direct C5−H bond arylation of thiazole derivatives. Under a low catalyst loading and performing the reactions at lower temperatures (80 °C) under aerobic conditions, we produced mono-and diarylated thiazole units. Competition experiments and density functional theory calculations revealed that the mechanism of C−H activation in 4-methylthiazole involves an electrophilic aromatic substitution.