A sustainable approach for nickel nanoparticles synthesis: expeditious access to N-heterocycles under heterogeneous condition and photophysical studies

Abstract

A sustainable and environmentally benign biogenic technique for one-step synthesis of Ni-NPs (NiC₂O₄·2H₂O-NPs) using Portulaca oleracea (purslane) leaf extract has been disclosed for the first time. The phytochemicals found in Portulaca oleracea leaf extract were found to serve as a reducing agent and subsequently act as a stabilizing agent. The various analytical and spectroscopic techniques confirm the formation of Ni-NPs. The catalytic potential of Ni-NPs was investigated to achieve cost-effective, sustainable, atom and step economic synthesis of pharmaceutically important quinazoline, 2-aminoquinoline, and N-(alkyl amino) quinoline via hydrogen auto transfer and acceptorless dehydrogenative annulation without the aid of external ligand and additives. Importantly, the photophysical property studies of the synthesized N-heterocycles are deliberated and gram-scale synthesis was achieved. Moreover, catalyst recyclability, control experiments, and mechanistic elucidation were elaborated.