Visible-Light-Triggered Monofluoromethylation of Alkenes by Strongly Reducing 1,4-Bis(diphenylamino)naphthalene Photoredox Catalysis

Monofluoromethyl (CH2F) radical can be easily generated from a sulfoximine-based precursor (CH2F-S(=O)-(=NTs)-Ph) by the action of visible-light metal-free photoredox catalysis with readily accessible 1,4-bis(diphenylamino)naphthalene. The catalyst design based on the high excitation energy (E-0,E-0) and interchromophoric conjugation features a strong reducing power and a high quantum yield of emission of the photocatalyst. In addition, their photophysical properties are preserved in various polar solvents. The present system is amenable to oxy-monofluoromethylation of alkenes with high functional-group tolerance, i.e., single-step synthesis of gamma-fluoroalcohol scaffolds from various alkenes. Applications to late-stage functionalization of potentially bioactive molecules are also shown.