Catalyst‐ and Oxidant‐Free Electrochemical Halogenation Reactions of 2H‐Indazoles with NaX (X=Cl, Br)

Abstract

An environmentally friendly and highly efficient electrochemical method has been developed for halogenation of 2H‐indazoles with cheap and commercially available NaX (X=Cl, Br) in the absence of metal catalysts and oxidants. Notably, this electrochemical process exhibits a broad substrate scope and high functional‐group compatibility. A variety of 2H‐indazoles are compatible with this transformation to give the corresponding products in modern to excellent yields. Also, this practical protocol avoids using external expensive supporting electrolytes. Last but not least, the procedure was carried out in an undivided cell at constant current condition under air atmosphere.

Design of Promising Thiazoloindazole-Based Acetylcholinesterase Inhibitors Guided by Molecular Docking and Experimental Insights

“…Once the indazole core is susceptible to halogenation at the C-3 position, , we decided to evaluate the possibility of obtaining fused-amino-thiazoloindazoles from indazole derivatives substituted at C-3 with a halogen atom (Scheme ). For this, the chlorination of 2a with N -chlorosuccinimide (NCS) was performed affording the chlorinated indazole 2e at C-3, in 58% yield.…”

A continuous flow electrochemical reactor using readily available metal wires and carbon fibers as electrodes: environmentally benign halogenations of alkenes, alkynes, and aromatics

“…31–39,40–48 And there has been much progress in electrochemical halogenation of alkenes, alkynes, and aromatics. 12–24 However, the use of flow-electrochemical halogenation is rare.…”

“…[31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48] And there has been much progress in electrochemical halogenation of alkenes, alkynes, and aromatics. [12][13][14][15][16][17][18][19][20][21][22][23][24] However, the use of flow-electrochemical halogenation is rare.…”

Electrochemical oxidative selective halogenation of pyrazolones for the synthesis of 4-halopyrazolones

“…[21][22][23][24][25][26][27] In recent years, there have been significant breakthroughs in the field of electrochemical halogenation. [28][29][30][31][32][33][34][35][36] To our best knowledge, the electrochemical oxidative halogenation of pyrazolones remains uncharted territory. Herein, we present a halogenation of pyrazolones via organic electrosynthesis that is both highly efficient and selective (Scheme 1c).…”