Chapter 5 - An evolution in electrochemical and chemical synthesis applications in prospects of ionic liquids

Abstract

This chapter throws light on the utility of room-temperature ionic liquids (RILs) in electrochemical and chemical synthesis to synthesize useful products with better yields at optimized conditions. RILs are utilized as an electrolyte and a solvent. RILs are found to be very advantageous due to their prominent features such as wider electrochemical windows, inherent conductivity, lower volatility, higher thermal stability, and tunability in electrochemical synthesis. Many RILs are made of cationic components such as tetraalkyl ammonium, imidazolium, pyrrolidinium, and piperidinium, and anionic components such as hexafluoroborate, tetrafluoroborate, and bis(trifluoromethanesulfonyl)imide were utilized for the electrochemical organic synthesis. Most of these salts are nontoxic, inexpensive, easily available, convenient, recyclable, reusable, energy efficient, and selective. Electrochemical oxidation reactions such as oxidative self-coupling, Shono oxidation, oxidation of alcohols to carbonyl compounds, and bromination in RILs are described thoroughly. Electrochemical reduction reactions which involved radical anion intermediates are stabilized by RILs and demonstrated. The N-heterocyclic carbenes are electrogenerated nucleophilic bases and catalyzed many reactions using RILs at optimized conditions to obtain maximum yields of desirable products. RILs were utilized for electropolymerization reactions. RILs were recovered and reused without affecting the yields of desirable products considerably in electrochemical organic synthesis. Furthermore, recent developments and some new approaches of electrochemical and chemical synthesis applications in prospects of RILs are also incorporated in this chapter.