An electrochemical N-acylation of carboxylic acids with amines was reported. The sustainable TBAB electrocatalysis proceeded with excellent chemoselectivity and positional selectivity, and with ample scope, allowing electrochemical N-acylation under mild reaction conditions at room temperature in water. Moreover, the synthetic utility of the current method is demonstrated by the synthesis of melatonin.

An efficient three-component reaction of 2-haloaniline, aldehyde, and ammonia in water catalyzed by CuI afforded benzimidazole derivatives in good to excellent yields up to 95%.

An environmentally friendly and efficient protocol for the synthesis of benzimidazoles by mortar–pestle grinding technique in the presence of acetic acid as a catalyst is reported. This mechanochemical method proceeded with the condensation of aldehyde and o-phenylenediamine followed by cyclization reaction, leading to the formation of the corresponding benzimidazoles in yields up to 97%. This protocol could also be applied for the synthesis of benzothiazoles and benzoxazoles. GRAPHICAL ABSTRACT

The development of protocols for synthesizing quinazolinones using biocompatible catalysts in aqueous medium will help to resolve the difficulties of using green and sustainable chemistry for their synthesis. Herein, using I₂ in coordination with electrochemical synthesis induced a C–H oxidation reaction which is reported when using water as the environmentally friendly solvent to access a broad range of quinazolinones at room temperature. The reaction mechanism strongly showed that I₂ cooperates electrochemically promoted the oxidation of alcohols, then effectively cyclizing amides to various quinazolinones.

Using eosin Y and KI as photocatalysts to facilitate the conversion of quinoxaline-2(1H)-one and phenylhydrazine hydrochloride compounds into corresponding 3-arylated quinoxaline-2(1H)-one, a simple and efficient synthesis method has been developed.

Microwave-assisted copper-catalyzed cascade reactions between 2-halobenzoic acids and amidines to synthesize quinazolinone derivatives in water are reported. A variety of target products were obtained in good to excellent yields up to 94%. Its application was performed by the synthesis of 4-(1H-benzo[d]imidazol-2-ylthio)-6-methoxypteridine, which displayed significant anti-proliferation effect.