Acceptorless Dehydrogenation under Neat Reaction Conditions: Synthesis of 2-Aryl/Alkyl Quinazolinones Using Supported Ni NPs as Catalyst

Abstract

We report here a Ni NPs catalyzed one-pot synthesis of 2-alkyl/aryl quinazolinone motifs via acceptorless dehydrogenation of alcohol, condensation with 2-aminobenzamide followed by second dehydrogenation of the cyclized intermediate. The protocol is atom-economical and uses earth-abundant Ni as the catalyst. The present report involves the annulation of 2-aminobenzamide with various types of primary alcohols, including aryl/heteroaryl methanols, and aliphatic alcohols, and produces high yields of the desired products under neat conditions. The catalyst was synthesized via high-temperature pyrolysis strategy, using ZIF-8 as the sacrificial template. The Ni NPs@N-C catalyst was characterized by XPS, HR-TEM, HAADF-STEM, XRD and ICP-MS. The catalyst is stable even in air at room temperature and displayed excellent activity in the acceptorless dehydrogenative coupling synthesis of quinazolinones and could be recycled five times without appreciable loss in its activity.