A catalyst- and solvent-free visible-light-promoted bromination and chlorination of tertiary C(sp3)–H bonds

Abstract

Previous methods for selective halogenation of aliphatic C–H bonds generally required catalysts, additives, and the use of large amounts of solvents, leading to low atom economy and solvent pollution issues. We report herein a visible-light-driven bromination/chlorination of 3° C(sp³)–H bonds without using any catalyst or solvent. This method can functionalize C–H bonds with high site selectivity and excellent functional group tolerance, even in complex molecules. Additionally, the reaction can be easily scaled up to gram-level production without losing efficiency.