Electro-Organic Synthesis of Heterocyclic Compounds

Abstract

Heterocyclic chemistry, a subfield of organic chemistry, focuses on the synthesis, properties, and applications of organic heterocycles. Traditionally, heterocyclic compounds were synthesized using conventional methods for chemo-, regio-, and stereo-selective synthesis. However, electro-organic synthesis has emerged as a sustainable alternative, eliminating the need for hazardous oxidants, and reductants. Based on principles derived from physical chemistry, electrochemical reactions drive various organic and inorganic transformations. Among these methods, multicomponent reactions have garnered significant attention worldwide in academia and industry. This comprehensive review critically examines the electrochemical organic synthesis of nitrogen-, oxygen-, and sulfur-containing heterocycles, encompassing an array of pivotal transformations from 2018 onward. Specifically, these reactions include dehydrogenative C–H alkylation, C–S cross-coupling, C–H cycloamination, radical cation-mediated organic transformations, sulfonylation, arylation, alkylation, geminal difluorination, oxotrifluoromethylation, and (3 + 2) cycloaddition reactions. Furthermore, this appraisal highlights the synthesis of bioactive molecules derived from these heterocyclic compounds, which exhibit exceptional biological properties and demonstrate significant potential in pharmaceutical applications. Notably, these electrochemical reactions are conducted under remarkably mild conditions, utilizing eco-friendly solvents within an electrochemical cell, thereby rendering the processes environmentally sustainable and greener.