A round-bottom flask was charged with K[B(C6F5)4] (0.720 g, 1 mmole) and Ph3CCl (0.280g, 1 mmole) in an argon glove box. The solids were dissolved in dichloromethane (~100 mL), and the reaction mixture was allowed to stir under an argon atmosphere. The solution became yellow-orange immediately. After stirring for 1 h, the solution was then filtered through Celite to remove KCl. The solvent volume was reduced to ~10 mL on a rotary evaporator to give a dark red oil. Addition of pentane resulted in yellow precipitate and a red oil. With sonication, the oil dispersed to give only yellow precipitate. The solid was isolated by filtration and dried in vacuo. Alternatively, the crude filtrate could be layered with pentane, and over the course of days to hours. Crystalline product formed. Isolated yield: 0.703 grams, 76%.
Yellow to mustard colored powder
Used as a pharmaceutical intermediate.
trityl tetrakis(pentafluorophenyl)borate is prepared by mixing LiB(C6F5)4 and trityl chloride in hexane and refluxing overnight. It is prepared also by one-pot procedure starting from bromopentafluorobenzene.
soluble in CH2Cl2, MeOH, and acetone, but its yellow color disappears because these solvents coordinate to the trityl salt.
