Hexamethyldisilane

[Experimental Procedure]
Cyanation of Cumene (R=i-Pr) : An oven-dried Schlenk tube equipped with a magnetic stir bar is evacuated and backfilled with O₂ three times. Cumene (0.5 mmol), N-iodosuccinimide (NIS) (1.05 eq., 0.525 mmol), Cu(ClO₄)₂·6H₂O (20 mol%, 0.1 mmol), acetonitrile (1.2 mL) are added into the tube and the reaction is stirred at 150°C for 1 hour. The reaction mixture is allowed to cool down. Under O₂, 1,10-phenanthroline (20 mol%, 0.1 mmol), TEMPO free radical (2 eq., 1 mmol), hexamethyldisilane (1 eq., 0.5 mmol) are added into the reaction mixture. The reaction is then heated up to 150°C for 2.5 days under O₂. After completion, the insoluble is removed by filtration. The filtrate is concentrated under vacuo and the residue is purified by column chromatography on silica gel using EtOAc / petroleum ether to give the corresponding p- or o-cyanated cumenes as a yellow liquid (65 mg, 90% yield, p:o = 6:1).