TBAI‐Promoted Electrochemical Cyclization: Synthesis of Quinazolines Using Cascade C—N Bond Generation

Abstract

Abstract An electrochemical cyclization strategy is employed herewith for the eco‐friendly and cost‐effective synthesis of 2‐substituted quinazolines by using 2‐aminobenzylamines and aldehydes or alcohols as starting substrates. The reactions were conducted under two distinct reaction temperatures: 25 °C for aldehydes and 60 °C for alcohols. Tetra‐ n ‐butylammonium iodide (TBAI) participates in dual roles such as, an electrolyte and a mild reagent to facilitate the formation of quinazolines at a constant current of 30 mA using a graphite electrode as anode and a platinum electrode as cathode in dimethyl sulfoxide (DMSO) solvent. Under the devised process, the quinazolines were accomplished with broad substrate scope in excellent yields (up to 90%), which reduces the formation of toxic side products. The plausible mechanistic pathways have been formulated, which are supported by the control experiments and cyclic voltammetry studies. The findings demonstrate that under electrochemical conditions, iodonium ions are generated, which play a crucial role in enhancing the efficacy of the described method.