Generation and Application of Iminyl Radicals from Oxime Derivatives Enabled by Visible Light Photoredox Catalysis

The advent of visible light photoredox catalysis has transformed the way of single-electron transfer (SET) processes and accessing radical species. As a result, the chemistry of nitrogen-centered radicals has witnessed a remarkable gain in interest. Specifically, under visible light photoredox catalysis, iminyl radicals can be generated from oxime derivatives, such as O-acyl oximes, O-aryl oximes and alpha-imino-oxy acids. Meanwhile, the reactivity of iminyl radcials is investigated systematically. Iminyl radicals can undergo four major classes of reactions, namely addition to arenes, intramolecular hydrogen atom transfer and subsequent reactions, addition to alkenes, Norrish type-I fragmentation (cleavage of alpha-carbon-carbon bonds) and subsequent reactions. In this review, the most significant progresses in the use of oximes and their derivatives as iminyl precursors are discussed and their engagement in photoredox-mediated transformations is outlined.