An Overview of α‐Aminoalkyl Radical Mediated Halogen‐Atom Transfer
An Overview of α‐Aminoalkyl Radical Mediated Halogen‐Atom Transfer
复制标题
α-氨基烷基自由基介导的卤素-原子转移概述
DOI：
10.1002/cctc.202300860
复制
发表时间：
2023
期刊：
影响因子：
4.5
通讯作者：
Laulhé, Sébastien
中科院分区：
文献类型：
--
作者：
Sachidanandan, Krishnakumar;Niu, Ben;Laulhé, Sébastien
卤素原子转移（XAT）过程与卤素原子转移（XAT）过程的合并已被证明是有机合成中产生碳中心自由基的通用工具。XAT工艺的独特之处在于，它们产生自由基，而不需要使用传统的单电子转移（SET）活化卤化物所必需的强还原剂。在合成应用中实现XAT的途径可以分为三个主要部分：i）杂原子基活化剂，ii）金属基活化剂，和iii）碳基活化剂，其中α-氨基烷基基团占据了中心舞台。在过去的几年里，由于反应的稳健性、所需试剂的简单性及其应用的广泛性，获得这些α-氨基烷基作为XAT试剂得到了极大的关注。这些α-氨基烷基的生成简单地通过叔胺的单电子氧化实现，叔胺在α-位去质子化后生成α-氨基烷基。由于可获得的叔胺的范围广以及所形成的α-氨基烷基自由基的可调亲核性，该策略已成为XAT的杂原子/金属基自由基的有吸引力的替代方案。在这篇简短的评论中，我们将重点关注最近（2020-2023）的发展和使用这种强大的技术来介导XAT过程。
The merging of photocatalysis with halogen‐atom transfer (XAT) processes has proven to be a versatile tool for the generation of carbon‐centered radicals in organic synthesis. XAT processes are unique in that they generate radicals without requiring the use of strong reductants necessary for the traditional single electron transfer (SET) activation of halides. Pathways to achieve XAT in synthetic applications can be categorized into three major sections: i) heteroatom‐based activators, ii) metal‐based activators, and iii) carbon‐based activators among which α‐aminoalkyl radicals have taken the center stage. Access to these α‐aminoalkyl radicals as XAT reagents has gained significant attention in the past few years due to the robustness of the reactions, the simplicity of the reagents required, and the broadness of their applications. Generation of these α‐aminoalkyl radicals is simply achieved through the single electron oxidation of tertiary amines, which after deprotonation at the α‐position generates the α‐aminoalkyl radicals. Due to the wide scope of tertiary amines available and the tunable nucleophilicity of α‐aminoalkyl radical formed, this strategy has become an attractive alternative to heteroatom/metal‐based radicals for XAT. In this minireview, we focus our attention on recent (2020–2023) developments and uses of this robust technology to mediate XAT processes.