Cu-catalyzed aryl C-H halogenation using N-halosuccinimides via assistance of benzoic acid

Abstract

Aryl halides are a kind of extremely valuable compounds used in transition-metal-catalyzed coupling reactions,as well as important structure motifs in many natural products and manufactured drugs[1,2].The classical approach for preparation of haloarenes is electrophilic aromatic substitution(EAS) using various halogenating reagents or oxidative halogenations with halogenating reagent generated in situ from halides and oxidants,such as peroxide,oxygen and meta-cholorperoxybenzoic acid(mCPBA)[3,4].However,harsh reaction conditions are required for halogenation of less active aromatics.orthoMetalation followed by halogen quenching is another approach for halogenation of aromatics[5].However,there are obvious drawbacks for these methods,such as low regioselectivity,harsh conditions and even dangerous procedures.Therefore,the development of an alternative and practical way remains challenge in organic synthesis.