Department of Chemistry, The University of Manchester, Oxford Road, Manchester, UK.
Chem Soc Rev. 2021 May 7;50(9):5349-5365. doi: 10.1039/d0cs00358a. Epub 2021 Mar 23.
Ketyl radicals are valuable reactive intermediates for synthesis and are used extensively to construct complex, functionalized products from carbonyl substrates. Single electron transfer (SET) reduction of the C[double bond, length as m-dash]O bond of aldehydes and ketones is the classical approach for the formation of ketyl radicals and metal reductants are the archetypal reagents employed. The past decade has, however, witnessed significant advances in the generation and harnessing of ketyl radicals. This tutorial review highlights recent, exciting developments in the chemistry of ketyl radicals by comparing the varied contemporary - for example, using photoredox catalysts - and more classical approaches for the generation and use of ketyl radicals. The review will focus on different strategies for ketyl radical generation, their creative use in new synthetic protocols, strategies for the control of enantioselectivity, and detailed mechanisms where appropriate.
酮基自由基是合成中非常有价值的反应中间体，广泛用于从羰基底物构建复杂的功能化产物。醛和酮的 C[双键，长度为破折号]O 键的单电子转移（SET）还原是形成酮基自由基的经典方法，金属还原剂是典型的试剂。然而，在过去的十年中，酮基自由基的产生和利用取得了重大进展。本综述通过比较不同的当代方法（例如使用光氧化还原催化剂）和更经典的方法，突出了酮基自由基化学的最新令人兴奋的发展。综述将重点介绍酮基自由基生成的不同策略、它们在新合成方案中的创造性应用、对对映选择性控制的策略以及在适当的情况下详细的机制。
