Electrochemical Synthesis of 5-(1H-indol-3-yl) N-Substituted-1,3,4-oxadiazole- 2-Amines: A Mild and Green Approach

Abstract

Abstract The electrochemical method for the synthesis of 5-(1H-indol-3-yl) N-substituted 1,3,4-oxadiazole-2-amines is a novel and efficient approach that offers several advantages over traditional synthetic methods. This method utilizes aliphatic and aromatic isothiocyanates as starting materials and employs electrochemical techniques to facilitate the reaction. The process begins with the selection of an appropriate electrochemical setup, typically involving a two-electrode system consisting of a working electrode and a counter electrode. The working electrode is made of a conductive material such as carbon. The reaction vessel contains a suitable electrolyte, which can be an organic solvent or an ionic liquid, depending on the specific requirements of the reaction. The reaction proceeds by applying a potential across the electrodes, creating an electric field that promotes the desired electrochemical transformations. The indole substrate and the isothiocyanate reagent are introduced into the reaction vessel, and upon the application of the appropriate potential, they undergo electrochemical oxidation and subsequent nucleophilic substitution to form the desired 1,3,4-oxadiazole-2-amines. One of the key advantages of this electrochemical method is its high functional group tolerance. The reaction can accommodate a wide range of functional groups present on both the indole substrate and the isothiocyanate reagents. This allows for the synthesis of diverse compounds with different substituents, providing access to a large substrate scope. Another notable advantage of this method is its good yield of the desired products. The electrochemical conditions can be optimized to ensure high conversion and selectivity, resulting in good overall yields of the 5-(1H-indol-3-yl) N-substituted 1,3,4-oxadiazole-2-amines. The reaction conditions can be fine-tuned to achieve the desired level of selectivity and efficiency. Furthermore, the facile nature of the electrochemical method makes it a convenient and sustainable alternative to traditional synthetic methods. Additionally, the use of electricity as an energy source can be more environmentally friendly compared to traditional heating methods.