Recent Advances in Electrochemical Synthesis of Nitriles: A Sustainable Approach

Abstract

Nitriles unveil widespread applications in pharmaceuticals, agrochemicals, textiles, rubber, polymers, and constitute a significant intermediate in several organic transformations, necessitating the design of simple and environmentally benign pathways for their synthesis. Over the recent years, electro‐organic reactions have found widespread attention in developing effective and selective organic synthesis. They possess several advantages: high atom economy, selectivity, minimal waste production, and shorter routes to multistep traditional organic reactions. The development of novel strategies for greener and sustainable electro‐organic synthesis of nitriles is therefore commendable. This review focuses on analyzing various methods and strategies used in the electrochemical synthesis of nitriles using phase transfer catalyst, N‐oxoammonium salts mediated electrocatalysis, iodine‐mediated electrocatalysis, and anodic oxidations of aldoximes. In addition, the recent trends including the synthesis of nitriles via C−H cyanation, domino oxidation, bio electrocatalysis, and metal‐ligand cooperative synthesis have been discussed.

CoSe2 Subnanometer Belts with Se Vacancies and Ni Substitutions for the Efficient Electrosynthesis of High-Value-Added Nitriles Coupled with Hydrogen Generation

“…1,2 Owing to its relatively favorable thermodynamic kinetics, the electrocatalytic amine oxidation reaction (AOR) has the potential to produce high-value-added products coupled with hydrogen generation. 3,4 Among the selective electrooxidation products of amines, nitriles have gained more respect due to their wide applications as essential building blocks and intermediates for agrochemicals, pharmaceuticals, and fine chemicals. 5−7 Typically, butyronitrile, one of the most common low-carbon nitriles, is a significant intermediate in the chemical and pharmaceutical industries and is also widely used in dyesensitized solar cells.…”

“…8−12 Moreover, the selectivity of the reported AOR catalysts is still unsatisfactory and is usually less than 95% at a moderate potential. 3,4 In this regard, developing new highly efficient AOR catalytic systems that both greatly reduce the reaction overpotential and enhance the selectivity is highly desirable yet remains a large challenge. Surface defect engineering has proven to be a practical and powerful approach for regulating the structure and performance of nanomaterials.…”

“…Water electrolysis has emerged as an attractive pathway for hydrogen generation. However, it is severely hindered by the slow anodic oxygen evolution reaction (OER). , Owing to its relatively favorable thermodynamic kinetics, the electrocatalytic amine oxidation reaction (AOR) has the potential to produce high-value-added products coupled with hydrogen generation. , Among the selective electrooxidation products of amines, nitriles have gained more respect due to their wide applications as essential building blocks and intermediates for agrochemicals, pharmaceuticals, and fine chemicals. − Typically, butyronitrile, one of the most common low-carbon nitriles, is a significant intermediate in the chemical and pharmaceutical industries and is also widely used in dye-sensitized solar cells. , Hence, coupling the AOR with the water reduction reaction is beneficial to rationally reduce the activation energy of water electrolysis and has scientific and industrial importance. However, despite the impressive progress in this field, this promising topic has not been fully explored with respect to either catalytic conversion processes or conversion efficiency optimization.…”

Tropylium‐BF4 as Organocatalyst for Efficient Synthesis of Nitriles from Aldoximes; Synthetic Scope and Mechanistic Insights

“…Moreover, the -CN group is a highly versatile synthon that can be converted to a number of other significant functional groups such as amides, amines, aldehydes, and ketones. [1][2][3][4][5] Whereas numerous methods for the synthesis of aromatic and aliphatic nitriles have been developed over the years, [1][2][3][4][5] the quest for the development of new, environmentally more acceptable, cyanide free methods continues. To this end, nitrile synthesis by dehydration of aldoximes has received considerable attention.…”

“…Nitrile groups are widely present in natural products, pharmaceuticals, dyes, and polymers. Moreover, the ‐CN group is a highly versatile synthon that can be converted to a number of other significant functional groups such as amides, amines, aldehydes, and ketones [1–5] . Whereas numerous methods for the synthesis of aromatic and aliphatic nitriles have been developed over the years, [1–5] the quest for the development of new, environmentally more acceptable, cyanide free methods continues.…”