Electrochemical Generation of Radicals

Making electrochemistry easily accessible to the synthetic chemist

“…During the last decade, electrochemistry has received renewed interest as a tool for synthetic chemistry. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] This is exemplified by whole journal issues being dedicated to synthetic electrochemistry. 18,19 Electrochemistry offers a very mild and atom efficient method to achieve selective oxidative or reduc-tive transformations using electrons as reactants.…”

The Standard Redox Potential of the Phenyl Radical/Anion Couple

“…They can be used in S RN 1 aromatic nucleophilic substitution by reaction with a nucleophile, − they can add to double bonds, giving rise to intramolecular cyclization reactions and − leading to the elegant synthesis of natural compounds such as cephalotoxinone and aspidospermidine, and they also lead to the modification of conductive surfaces: carbon, metals, or semiconductors . Aryl radicals can be prepared through different means: (i) chemical reduction of an aryl halide with NaBH 4 , with alkali metals in liquid ammonia, with Fe 2+ , SmI 2 , or sodium amalgam, but also through the radical-polar crossover reaction which involves a one-electron reduction of diazonium salt by an easily oxidized sulfide such as tetrathiafulvalene; (ii) photochemistry; and (iii) electrochemistry, a very convenient mean of generating aryl radicals through a one-electron reduction of an aryl derivative (halide, sulfide, ether, etc. ), as shown in Scheme .…”

Overview of Recent Scale-Ups in Organic Electrosynthesis (2000–2023)

“…Waldvogel reported examples of phenolic oxidative dimerizations via oxidation of tetraphenoxyborate derivatives, such as the conversion of 24 to 25 initially starting from 26 (Scheme 10). 111,112 The electrolyses were performed in acetonitrile using either a batch setup (beaker-type cell, 21 cm 2 Pt electrode) 113 or a capillary gap reactor (flow, 734 cm 2 graphite electrode). 114 No detailed synthetic procedure or photos of the setup were reported for the kilogram-scale experiment, although the authors referenced a 1969 publication 114 material (platinum vs graphite) and the change in reactor type (batch beaker-type cell vs capillary gap flow reactor).…”

“… a Schematics reproduced with permission from (bottom left) ref and (bottom right) ref . Copyright 2001 and 1969, respectively, Wiley-VCH. …”