Photocatalytic Deuterium Atom Transfer Deuteration of Electron‐Deficient Alkenes with High Functional Group Tolerance

Due to its mild reaction conditions and unique chemoselectivity, hydrogen atom transfer (HAT) hydrogenation represents an indispensable method for the synthesis of complex molecules. Its analog using deuterium, deuterium atom transfer (DAT) deuteration, is expected to enable access to complex deuterium‐labeled compounds. However, DAT deuteration has been scarcely studied for synthetic purposes, and a method that possesses the favorable characteristics of HAT hydrogenations has remained elusive. Herein, we report a protocol for the photocatalytic DAT deuteration of electron‐deficient alkenes. In contrast to the previous DAT deuteration, this method tolerates a variety of synthetically useful functional groups including haloarenes. The late‐stage deuteration also allows access to deuterated amino acids as well as donepezil‐d2. Thus, this work demonstrates the potential of DAT chemistry to become the alternative method of choice for preparing deuterium‐containing molecules. A synthetically benign deuterium atom transfer (DAT) deuteration of electron‐deficient alkenes has been achieved. This DAT protocol realized higher functional group (FG) tolerance and chemoselectivity than the existing method, and allowed access to complex deuterated compounds including a heavy drug and deuterium‐labeled amino acids.