NMR data for 37f. tris(1,1,1,3,3,3-hexafluoro-2-(trifluoromethyl)propan-2-yl) borate. 11B

Under an atmosphere of argon, a flame dried 2-necked round bottom flask equipped with a condenser was charged with perfluoro-tert-butanol (7.5 ml, 12.75g, 54 mmol, 3.15 eq.) and cooled to 0 °C. Borane dimethylsulfide (1.7 ml, 17 mmol, 1 eq) was added dropwise, and after 30 minutes the cold bath was removed and the reaction heated to reflux overnight. After this time 1 ml further perfluoro-tert-butanol was added and reflux was continued for 2 hours. After this time the borate was purified by distillation (100 °C, 40 mbar) and collected as a white solid. The solid was melted by gentle heating and solid impurities were removed by filtration. Yield = 5.75 g colourless liquid, 47%. Due to poor solubility in typical NMR solvents, analysis was carried out in anhydrous diethyl ether. NMR data is in accordance with literature reports.