Recent Advances in Electrochemical Cascade Cyclization Reactions

Abstract This review highlights recent progress in electrochemical cascade cyclization reactions for the synthesis of carbon rings and heterocycles, such as pyridines, quinolines, phenanthridines, cinnolines, 1,4-dihydroquinolines, oxindoles, imidazo[1,5-α]pyridines, imidazoles, etc. The works included herein are introduced in two major sections of heterocycle construction and carbocycle construction reactions, covering the works reported from 2012 to 2022. 1 Introduction 2 Electrochemical Cascade Cyclization for the Synthesis of Heterocycles 2.1 Synthesis of Pyridines, Quinolines, Phenanthridines, and Cinnolines 2.2 Synthesis of 1,4-Dihydroquinolines, Hexacyclic Sulfonamides, and Thiazines 2.3 Synthesis of Hydroisoquinolinones and Hydroquinolinones 2.4 Synthesis of Quinazolin-4(3H)-ones 2.5 Synthesis of 4H-3,1-Benzoxazines 2.6 Synthesis of Oxindoles 2.7 Synthesis of Indolines and Indoles 2.8 Synthesis of Imidazo[1,5-α]pyridines and Imidazoles 2.9 Synthesis of Imidazolones, Imidazolidinones, Oxazolones, and Oxazolidinones 2.10 Synthesis of Benzoxazoles, Oxazolines, and Isoxazolines 2.11 Synthesis of Furans and Dihydrofurans 2.12 Synthesis of Indolizines, Pyrazoles, and Triazolium Inner Salts 2.13 Synthesis of Sulfonated Benzothiophenes, Thiazoles, Dihydrothiazoles, and 1,3,4-Thiadiazoles 2.14 Synthesis of Lactones 3 Electrochemical Cascade Cyclization for the Construction of Carbocycles 3.1 Synthesis of Carbon Polycycles and Spiroindenes 3.2 Synthesis of Difluoroacyl (Hetero)arenes and Sulfonated Indenones 4 Conclusion