Synthesis and lewis acidity of fluorinated triaryl borates.

A series of fluorinated triaryl borates B(OAr F ) 3 (Ar F = 2-FC 6 H 4 , 3-FC 6 H 4 , 4-FC 6 H 4 , 2,4-F 2 C 6 H 3 , 3,5-F 2 C 6 H 3 , 2,3,4-F 3 C 6 H 2 , 2,4,6-F 3 C 6 H 2 , 3,4,5-F 3 C 6 H 2 ) have been prepared and isolated from the reactions of the mono-, di-, or tri-fluorophenol with BCl 3 . The Lewis acidity of these borates has been determined by NMR spectroscopic and theoretical methods and compared to their well-established borane counterpart.