近日，美国威斯康星大学麦迪逊分校Zachary K. Wickens团队报道了选择性源于非选择性光还原。相关论文于2026年7月15日发表在《自然》杂志上。

单电子转移（SET）还原是活化有机化合物最基本策略之一。基于SET设计选择性反应的前提是，底物氧化还原电位的差异可预测SET的相对速率，即更易被还原者反应更快。然而，在多种氧化还原催化模式中，设计需要SET作用于两种反应物中更难被还原的那一种的反应仍颇具挑战。这一限制几乎排除了针对热力学上难以还原或氧化的底物进行偶联反应的可能性。

研究组提出了一种适用于外球SET的替代选择性范式，该范式与底物氧化还原电位无关。他们证明，超强光还原剂通过扩散限制的SET使底物氧化还原电位不再重要，从而使下游化学步骤与反向电子转移（BET）之间的竞争决定新的选择性分布。研究组在环丙基酮与更易还原的烯烃之间的自由基成环反应中验证了上述原理。

尽管此前不匹配的氧化还原电位阻碍了此类反应，但即使在所需的酮还原在热力学上不利（差一个伏特）的情况下，研究组仍能促进选择性自由基成环反应。更广泛地说，这些研究为设计需要打破氧化还原电位控制的SET反应提供了通用蓝图。

附：英文原文

Title: Selectivity Emerges from Indiscriminate Photoreduction

Author: Edgecomb, Joseph M., Sau, Arindam, Manoj, Niket, Resmini, Matthew D., Meyer, Alissia F., Paton, Robert S., Damrauer, Niels H., Wickens, Zachary K.

Issue&Volume: 2026-07-15

Abstract: Single electron transfer (SET) reduction is amongst the most fundamental strategies for the activation of organic compounds. The design of selective reactions that leverage SET is grounded by the premise that differences in substrate redox potentials predict relative rates of SET, with more favorable reductions occurring faster.1 However, across the diverse modes of redox catalysis,2,3 devising reactions that require SET to the harder-to-reduce of two reactants remains challenging. This restriction all but precludes coupling reactions when targeting substrates that are thermodynamically difficult to reduce or oxidize.4,5 Here, we introduce an alternative selectivity paradigm for outer sphere SET that is divorced from substrate redox potentials. We show that super-potent photoreductants render substrate redox potentials irrelevant through diffusion-limited SET, allowing a new selectivity profile to emerge from competition between downstream chemical steps and back electron transfer (BET). We validate these principles in the context of radical annulation reactions between cyclopropyl ketones and easier-to-reduce alkenes. While these mismatched redox potentials previously precluded such reactions, we promote selective radical annulation even as the requisite ketone reduction becomes disfavored by a volt. More broadly, these studies offer a general blueprint for the design of SET reactions that require violation of redox potential control.

DOI: 10.1038/s41586-026-10897-7

Source: https://www.nature.com/articles/s41586-026-10897-7

期刊信息

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504

官方网址：http://www.nature.com/

投稿链接：http://www.nature.com/authors/submit_manuscript.html