Photo/Electrochemical‐Mediated C(sp³)−H Bond Functionalization of (Thio)Ethers

Abstract

Molecules containing ether skeletons are widely present in drugs, natural products, functional materials, and life science. Direct C(sp3)–H bond ether functionalization is considered a powerful strategy for the construction of novel ether derivatives. Photo‐/electro‐chemical technology is a relatively green and sustainable synthesis method, which opens up a broad application prospect in the field of direct functionalization of C(sp3)–H bonds. In recent years, photo‐/electro‐mediated C(sp3)–H bond alkylation, arylation, alkynylation, esterification, mercaptoylation, sulfidation, and amination of ethers have been extensively studied. In this review, the research progress of photo‐/electro‐mediated C(sp3)–H bond functionalization of ether compounds from 2014 to 2023 is systematically reviewed, and the scope, limitations, and mechanisms for some reactions are discussed.

Minisci-Type Dehydrogenative Coupling of C(sp3)–H and N-Heteroaromatics Enabled by Photoelectrochemical Hydrogen Atom Transfer

“…However, the formation of nucleophilic carbon radicals typically necessitates the use of functionalized radical precursors, such as organoboron reagents, alkylpyridinium salts, and others (Scheme a) . The direct participation of C­(sp 3 )–H compounds in the reaction is considered to be a highly desirable strategy . However, in the case of C­(sp 3 )–H bonds, such as that α to heteroatoms (ethereal, α to alcohol or amide N atom), a high bond dissociation enthalpy has to be overcome .…”