Photoredox-catalyzed direct C–H monofluoromethylation of heteroarenes

Abstract

Fluoroalkyl groups play a vital role in pharmaceutical products and agrochemicals, where their installation onto aryl and heterocyclic rings can often lead to enhanced physicochemical and biological properties. Among them, heterocycles containing monofluoromethyl groups are an appealing but scarcely investigated class of organofluorine compounds with potential applications in medicinal chemistry. Here we report that an iodine(III) reagent containing monofluoroacetoxy ligands can be used to transfer monofluoromethyl radicals to heterocycles via visible-light photoredox catalysis, allowing for the mild, direct, and operationally simple modification of medicinally relevant heterocycles through a Minisci-like C–H functionalization process. This approach enriches the synthesis of a structurally diverse set of heteroaromatics incorporating monofluoromethyl groups in moderate to excellent yields. The practicability of direct C–H radical monofluoromethylation for late-stage modifications of medicinally relevant biomolecules and drugs is also demonstrated. Moreover, the monofluoromethylated heterocyclic compounds exhibit promising antimicrobial and anticancer activities, indicating that this methodology might assist in drug discovery as a dependable tool for lead drug modification in the development of new small-molecule drugs.