Halogen exchange in reactions of boron halides with o-(trifluoromethyl)-phenyltrimethyl derivatives of silicon and tin

Abstract

The reaction of boron trifluoride with o-CF3C6H4SnMe3 in carbon tetrachloride gives o-CF3C6H4BF2, which with aqueous potassium fluoride is converted to K[o-CF3C6,H4BF3]. Boron trichloride and o-CF3C6H4SnMe3 undergo halogen exchange to give, after hydrolysis, o-CCl3C6H4B(OH)2. Halogen exchange also occurs between boron trichloride and o-CF3C6H4Y (Y = H, SiMe3) to give boron trifluoride and o-CCl3C6H4Y. The long range HF and FF nuclear magnetic resonance (n.m.r.) coupling constants observed for o-CF3C6H4-derivatives are briefly discussed.