We describe a catalytic strategy for direct single C­(sp3)–F bond alkylation of trifluoromethylbenzimidazoles under a photoinduced thiol catalysis process. The CO2 radical anion (CO2 •–) proved to be the most efficient single-electron reductant to realize such a transformation. The spin-center shift of the generated radical anion intermediate is the key step in realizing C–F bond activation under mild conditions with high efficiency.

The regio- and diastereoselective hydroboration of N-aryl enamine carboxylates was achieved by dichloro-substituted N-heterocyclic carbene (NHC)-boryl radical to access the valuable anti-β-amino boron skeleton. Excellent diastereoselectivity (>95:5 dr) was obtained using dichloro-NHC–BH3 (boryl radical precursor) and the thiol catalyst. Broad substrate scope and good functional group tolerance were demonstrated. Further transformation of the product to amino alcohol exemplified the synthetic utility of this reaction.

A silyl radical-triggered radical addition-translocation-cyclization (RATC) process followed by chemo-divergent conversions was developed to construct structurally diverse silicon-incorporated indolines. The reaction proceeds via a sequence of silyl radical addition, 1,5-hydrogen...