Electroreduction of aromatics using magnesium electrodes in aprotic solvents containing alcoholic proton donors

Synthetic Organic Electrochemical Methods Since 2000: On the Verge of a Renaissance

“…670–672 Ishifune and co-workers developed an electrochemical Birch-type reduction in t BuOH (Figure 41D, left). 673 The use of Mg electrodes was critical. It was postulated that anodically generated Mg(II) mediates electron transfer.…”

Scalable and safe synthetic organic electroreduction inspired by Li-ion battery chemistry

“…(12,13,15,36,42,43,48) To help probe the functional-group tolerance of these prior works, we opted for phenyl ethanol (3) as a model substrate. The conditions reported by Kashimura (15) were chosen as a basis set from which to launch more extensive optimization (entry 4); however, the limitations of that state-of-theart were clearly demonstrated in that 3's alcohol moiety completely shut down reactivity under Kashimura's conditions. To optimize, LiClO 4 was first replaced with LiBr due to the bromide salt's higher stability, affordability, and similar range of solubility; however, only trace product was detected (entry 5).…”

Electrode Materials in Modern Organic Electrochemistry

“…Thereaction was shown to be highly scalable and remarkably tolerant to av ery wide range of substrates. [91] In an earlier study of the same reaction (Figure 19 A), [86] Mg anodes were also found to give the highest yields,which was proposed to be due to Mg 2+ ions acting as electron transfer catalysts or stabilising anionic intermediates and promoting their reduction. Mechanistic studies were undertaken by Baran to elucidate if liberated Mg 2+ ions played ab eneficial role in the reaction.…”

“…[83,84] Optimisation of the electrode material is akey task in remedying this effect (Figure 5B). Other methods that have been shown to be effective include pulse electrolysis, [85] sonication, [86] alternating the polarity of the electrodes (which can also effect the reaction selectivity or yield), [87][88][89] and the use of mediators to shuttle redox equivalents from the electrode to the substrate in the bulk phase. [75,90] Alternatively,the addition of additives can increase the solubility of the insulating polymer in the electrolyte or protect the electrode surface,w hich has been shown to be highly effective in arecent electrochemical Birch reduction.…”