Regioselective Direct C−H Bond (Hetero)arylation of Thiazoles Enabled by a Novel Iminopyridine-Based α‐Diimine Nickel(II) Complex Evaluated by DFT Studies.

Direct C−H bond arylation is a highly effective method for synthesizing arylated heteroaromatics. This method reduces 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 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 (DFT) revealed that the mechanism of C−H activation in 4-methylthiazole involves electrophilic aromatic substitution.