Nickel-catalysed dehydrogenative coupling of aromatic diamines with alcohols: selective synthesis of substituted benzimidazoles and quinoxalines

The first nickel- catalysed dehydrogenative coupling of primary alcohols and ethylene glycol with aromatic diamines for selective synthesis of mono- and di- substituted benzimidazoles and quinoxalines is reported. The earth- abundant, non- precious and simple NiCl2/ L1 system enables the synthesis of N- heterocycles releasing water and hydrogen gas as byproducts. Mechanistic studies involving deuterium labeling experiments and quantitative determination of hydrogen gas evaluation were performed.