Vicinal Difunctionalization of Alkenes Using Vinyl Triflates Leading to γ-Trifluoromethylated Ketones.

We report a new methodology for the synthesis of γ-trifluoromethylated ketones from alkenes and vinyl triflate bifunctional reagents. The reaction proceeds via the addition of a β-trifluoromethyl alkyl radical to a vinyl triflate, followed by β-cleavage. We also demonstrate a one-pot version of the reaction for the vicinal functionalization of alkenes from alkynes.

Redox-Neutral Tetrafluoroethylation of Aryl Alkynes with 1,1,2,2-Tetrafluoroethane Sulfonic Acid Leading to α-Tetrafluoroethylated Acetophenones.

The redox-neutral tetrafluoroethylation of alkynes with 1,1,2,2-tetrafluroroethanesulfonic acid (TFESA) and azobis(isobutyronitrile) (AIBN) proceeds via the formation of vinyl tetrafluoroethanesulfonates followed by a radical tetrafluoroethylation. Experimental and theoretical results support an intermolecular reaction.

Inverse Hydroboration of Imines with NHC-Boranes Is Promoted by Diphenyl Disulfide and Visible Light.

We describe a simple and efficient procedure for nucleophilic borylation of imines in the absence of a photoredox catalyst. Visible light irradiation of an acetonitrile solution of an imine, an NHC-borane, and diphenyl disulfide (10 mol %) provides various stable α-amino NHC-boranes in good yields. The reaction proceeds via addition of a nucleophilic boryl radical to an imine, followed by hydrogen abstraction from thiophenol, which is generated from NHC-borane and diphenyl disulfide.