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 (E0,0) 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 γ-fluoroalcohol scaffolds from various alkenes.
Applications to late-stage functionalization of potentially bioactive
molecules are also shown.