Chloro[1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene]gold(I)

Regio- and stereoselective hydrofluorination reaction

Typical procedure: To a 2 mL polypropylene microcentrifuge tube is added the alkyne substrate (131 mg), PhN(CH3)3• HOTf (11 mg), Chloro[1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene]gold(I) (6 mg), AgBF4 (2 mg) and CH2Cl2 (0.75 mL) are added. After stirring in the dark for 5 min, KHSO4 (40 mg) and Et3N• 3HF (100 micro-L) are added. The reaction is stirred in the dark for 15 h. The reaction mixture is transferred to a 15-mL polypropylene centrifuge tube. The reaction is quenched by adding excess Cs2CO3 to the reaction mixture until gas evolution ceased. The mixture is filtered through celite, which is subsequently rinsed with CH2Cl2 (5 mL). The solvent is removed in vacuo. The crude residue is purified by flash column chromatography to give the hydrofluorination product in 74% yield as a clear oil.

• B. C. Gorske, C. T. Mbofana, S. J. Miller, Org. Lett. 2009, 11, 4318.