Electrochemically Driven Hydrogen Atom Transfer Catalysis: A Tool for C(sp3)/Si–H Functionalization and Hydrofunctionalization of Alkenes

Electrochemically driven hydrogen atom transfer (HAT) catalysis provides a complementary approach for the transformation of redox-inactive substrates that would be inaccessible to conventional electron transfer (ET) catalysis. Moreover, electrochemically driven HAT catalysis could promote organic transformations with either hydrogen atom abstraction or donation as the key step. It provides a versatile and effective tool for the direct functionalization of C(sp3)–H/Si–H bonds and the hydrofunctionalization of alkenes. Despite these attractive properties, electrochemically driven HAT catalysis has been largely overlooked due to the lack of understanding of both the catalytic mechanism and how catalyst selection should occur. In this Review, we give an overview of the HAT catalysis applications in the direct C(sp3)–H/Si–H functionalization and hydrofunctionalization of alkenes. The mechanistic pathways, physical properties of the HAT mediators, and state-of-the-art examples are described and discussed.