Photoredox functionalization of C–H bonds adjacent to a nitrogen atomLei Shi, Wujiong Xia|Chemical Society Reviews|2012 The functionalization of C-H bonds and the visible light photoredox catalysis represent two prominent challenges in organic chemistry. In this regard, the combination of visible-light catalysis and C-H bond functionalization adjacent to a tertiary amine has been successfully developed in the past three years. In this tutorial review, we aim to give a brief overview of this issue and state the main results obtained in the reactions.
Iron-Catalyzed C(Sp<sup>3</sup>)–H Borylation, Thiolation, and Sulfinylation Enabled by Photoinduced Ligand-to-Metal Charge TransferJia‐Lin Tu, Ao-Men Hu, Lin Guo et al.|Journal of the American Chemical Society|2023 Catalytic C(sp3)–H functionalization has provided enormous opportunities to construct organic molecules, facilitating the derivatization of complex pharmaceutical compounds. Within this framework, direct hydrogen atom transfer (HAT) photocatalysis becomes an appealing approach to this goal. However, the viable substrates utilized in these protocols are limited, and the site selectivity shows preference to activated and thermodynamically favored C(sp3)–H bonds. Herein, we describe the development of undirected iron-catalyzed C(sp3)–H borylation, thiolation, and sulfinylation reactions enabled by the photoinduced ligand-to-metal charge transfer (LMCT) process. These reactions exhibit remarkably broad substrate scope (>150 examples in total), and most importantly, all of these three reactions show unconventional regioselectivity, with the occurrence of C(sp3)–H borylation, thiolation, and sulfinylation preferentially at the distal methyl position. The procedures are operationally simple and readily scalable and provide access to high-value products from simple hydrocarbons in one step. Mechanistic studies and control experiments indicate that the afforded site selectivity is not only relevant to the HAT species but also largely affected by the use of boron- and sulfone-based radical acceptors.