Solvent-Free Mechanoradical-Mediated Minisci-Type C–H Alkylation of N-Heteroarenes
Xiang Gu, Taoyong Wang, KaKing Yan
Abstract
An environmentally friendly new C–H alkylation method of N-heteroarenes facilitated by mechanochemistry is described. Under solvent-free ball-milling, mechanoradicals (SO 4 •– ) were generated from persulfate via in situ homolysis in the solid state, at as low as −50 °C. These highly oxidizing radicals readily transform alkyl trifluoroborate salts to their corresponding carbon-based radicals for subsequent C–C bond formation with N-heterocycles. Mechanistic studies unambiguously confirmed the involvement of both oxygen- and alkyl-radical-based intermediates.
Topics & Concepts
ChemistryHomolysisRadicalAlkylationOxidizing agentAlkylMechanochemistrySolventPersulfateOrganic chemistryPhotochemistryCatalysisRadical Photochemical ReactionsCatalytic C–H Functionalization MethodsPhenothiazines and Benzothiazines Synthesis and Activities