Investigations on the 1,2-Hydrogen Atom Transfer Reactivity of Alkoxyl Radicals under Visible-Light-Induced Reaction Conditions

Abstract

AbstractThe alkoxyl radicals have demonstrated superior hydrogen atom transfer reactivity in organic synthesis due to the strong oxygen–hydrogen bond dissociation energy. However, only the intermolecular hydrogen atom transfer (HAT) and intramolecular 1,5-HAT have been widely studied and synthetically utilized for C(sp3)–H functionalization. This Account summarizes our investigations on the unusual 1,2-HAT reactivity of alkoxyl radicals under visible-light-induced reaction conditions for the α-C–H functionalization. Various mechanistic investigations were discussed in this Account to address three key questions to validate the 1,2-HAT reactivity of alkoxyl radicals.1 Introduction2 Could Aldehydes/Ketones Be the Sole Reaction Intermediate for the α-C–H Allylation? NO3 Is the Alkoxyl Radical Absolutely Involved in the Reaction? YES4 Does the 1,2-HAT of Alkoxyl Radicals Irrefutably Exist? YES5 Conclusion