Rate increases in the fluorination of bulky chlorosilanes caused by ultrasound or by water

The conversion of bulky chlorosilanes to fluorosilanes under anhydrous conditions with hexafluorosilicate salts is accelerated by ultrasound. The fluorination of sterically hindered chlorosilanes such as ^tBuPh₂SiCl, in the absence of ultrasound, is greatly accelerated by the addition of water to the reaction mixture.