Electro-organic synthesis: an environmentally benign alternative for heterocycle synthesis

Abstract

In recent years, there has been a gradual shift from traditional methodologies to electrochemically mediated organic synthesis. The present review outlines the utility of electrochemically mediated strategies in heterocylic synthesis.

Radical coupling reactions of hydrazinesviaphotochemical and electrochemical strategies

“…Electrosynthesis has become one of the most efficient, green and sustainable methods for redox transformations in organic synthesis. 10 In 2018, Yu and co-workers reported cobalt-catalyzed C–H oxidative coupling of N -arylacrylamides with arylhydrazines under the electrochemical conditions (Scheme 11). 17 This procedure provided a novel strategy for the synthesis of various substituted oxindoles and avoided the use of stoichiometric oxidants.…”

“…Photo- and electrochemistry have recently been attracting increasing attention from the synthetic community, which have shone new light on radical chemistry. 9,10 More Recently, hydrazines have been also utilized as coupling partners for the formation of carbon–carbon and carbon–heteroatom bonds under the photochemical and electrochemical conditions. In most cases, radical species via a denitrogenation process have participated in oxidative coupling reactions.…”

Catalyst-free electrochemical trifluoromethylation of coumarins using CF3SO2NHNHBoc as the CF3 source

“…Electrochemical synthesis has emerged as a powerful and environmentally friendly synthetic strategy. [26][27][28][29][30] Various common trifluoromethylation reagents such as CF 3 SO 2 Na (Langlois reagent), 31 Zn(CF 3 SO 2 ) 2 (Baran's reagent) 32 and CF 3 SO 2 Cl 33 have been used extensively in electrochemical reactions to develop new trifluoromethylation methods. [34][35][36] Sulfonyl hydrazides, considered as alternatives to sulfinic salts or sulfonyl halides, are widely used in organic synthesis.…”

Recent Progress in Heterocycle Synthesis: Cyclization Reaction with Pyridinium and Quinolinium 1,4-Zwitterions

“…Heterocycles are ubiquitous cores in natural products, bioactive molecules, functional materials, and therapeutic leads [ 1 , 2 , 3 , 4 ]. Chemists are becoming increasingly focused on developing efficient synthetic approaches for heterocyclic frameworks, where minimizing the number of synthetic steps, maximizing synthesis efficiency, and reducing side reactions are important evaluation criteria [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. Among various synthetic strategies, dipolar cyclization reactions have become one of the most favored methods for the construction of functionalized heterocyclic compounds [ 16 , 17 , 18 , 19 , 20 ].…”