Cutting it close for radical coupling In principle, electrochemistry is an ideal method for radical coupling: One precursor oxidized at the anode pairs up with a counterpart that has been reduced at the cathode. The trouble is that either or both coupling partners might not stay stable long enough to meet in the middle. Mo et al. resolved this issue by closely spacing the electrodes in a microfluidics platform (see the Perspective by Liu et al.). They showcase coupling of dicyanobenzene as the cathodic radical precursor with a variety of oxidatively generated partners. Science, this issue p. 1352; see also p. 1312 Closely spaced electrodes promote coupling between radicals respectively generated by oxidation and reduction. Electrochemistry offers opportunities to promote single-electron transfer (SET) redox-neutral chemistries similar to those recently discovered using visible-light photocatalysis but without the use of an expensive photocatalyst. Herein, we introduce a microfluidic redox-neutral electrochemistry (μRN-eChem) platform that has broad applicability to SET chemistry, including radical-radical cross-coupling, Minisci-type reactions, and nickel-catalyzed C(sp2)–O cross-coupling. The cathode and anode simultaneously generate the corresponding reactive intermediates, and selective transformation is facilitated by the rapid molecular diffusion across a microfluidic channel that outpaces the decomposition of the intermediates. μRN-eChem was shown to enable a two-step gram-scale electrosynthesis of a nematic liquid crystal compound, demonstrating its practicality.

中文翻译：

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用于单电子转移氧化还原中性反应的微流体电化学

切断自由基耦合 原则上，电化学是自由基耦合的理想方法：在阳极氧化的一种前体与在阴极还原的对应物配对。问题是耦合伙伴中的一个或两个可能无法保持稳定足够长的时间在中间相遇。莫等人。通过将微流体平台中的电极紧密间隔来解决这个问题（参见 Liu 等人的观点）。他们展示了作为阴极自由基前体的二氰基苯与各种氧化生成的伙伴的偶联。科学，这个问题 p。1352; 另见第 1312 紧密间隔的电极促进氧化和还原分别产生的自由基之间的耦合。电化学为促进单电子转移 (SET) 氧化还原中性化学提供了机会，类似于最近使用可见光光催化发现的化学，但不使用昂贵的光催化剂。在此，我们介绍了一种微流体氧化还原-中性电化学 (μRN-eChem) 平台，该平台对 SET 化学具有广泛的适用性，包括自由基交叉偶联、Minisci 型反应和镍催化的 C(sp2)-O 交叉偶联. 阴极和阳极同时产生相应的反应中间体，并且通过微流体通道上的快速分子扩散超过中间体的分解，促进了选择性转化。μRN-eChem 被证明可以实现向列液晶化合物的两步克级电合成，