Inhibition of Stannane-Mediated Radical Rearrangements by a Recoverable, Minimally Fluorous Selenol

Hydroarylation of Arenes via Reductive Radical-Polar Crossover

A photocatalytic system for the dearomative hydroarylation of benzene derivatives has been developed. Using a combination of an organic photoredox catalyst and an amine reductant, this process operates through a reductive radical-polar crossover mechanism where aryl halide reduction triggers a regioselective radical cyclization event, followed by anion formation and quenching to produce a range of complex spirocyclic cyclohexadienes. This light-driven protocol functions at room temperature in a green solvent system (aq. MeCN) without the need for precious metal-based catalysts or reagents or the generation of stoichiometric metal byproducts.

Efficient conversion of vicinal diols to alkenes by treatment of the corresponding dimesylates with a catalytic, minimally fluorous, recoverable diaryl diselenide and sodium borohydride

In conjunction with sodium borohydride as stoichiometric reagent a catalytic quantity of bis(4-perfluorohexylphenyl) diselenide converts vicinal dimesylates to the corresponding alkenes in good yield on warming in ethanol. The diselenide is recovered in high yield by continuous fluorous extraction.

Efficient one-pot conversion of carbonyl compounds to their alpha,beta-unsaturated derivatives using a recoverable, minimally fluorous organoselenium reagent

A protocol for the preparation of a fluorous arylselenenyl chloride is described. This selenenyl chloride may be used for the direct alpha-selenation of ketones and, following oxidation and syn-elimination, formation of alpha,beta-unsaturated carbonyl compounds. Treatment of the crude reaction mixtures with sodium metabisulfite reduces the various selenium species to the diaryl diselenide, which is then recovered in high yield by continuous fluorous extraction.