Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
Curr Opin Chem Biol. 2019 Apr;49:16-24. doi: 10.1016/j.cbpa.2018.09.001. Epub 2018 Sep 27.
Initiating and terminating free-radical reactionis via hydrogen atom transfer (HAT) is an attractive means of avoiding substrate prefunctionalization. Small molecule catalysts and reagents, however, struggle to execute this fundamental step with useful levels of diastereoselectivity and enantioselectivity. In contrast, nature often carries out HAT with exquisite levels of selectivity for even electronically unactivated carbon-hydrogen bonds. By understanding how enzymes exploit and control this fundamental step, new strategies can be developed to address several long-standing challenges in free-radical reactions. This review will cover recent discoveries in biocatalysis that exploit a HAT mechanism to either initiate or terminate novel one-electron reactions.
通过氢原子转移（HAT）引发和终止自由基反应是避免底物预官能化的一种有吸引力的方法。然而，小分子催化剂和试剂在执行这一基本步骤时，很难达到有用的非对映选择性和对映选择性水平。相比之下，自然界通常可以非常精确地进行 HAT，即使是对电子未激活的碳氢键也是如此。通过了解酶如何利用和控制这一基本步骤，可以开发新的策略来解决自由基反应中的几个长期存在的挑战。本文综述了生物催化中利用 HAT 机制引发或终止新型单电子反应的最新发现。
