Polyfluoroorganotrifluoroborates and -difluoroboranes: interesting materials in fluoroorgano and fluoroorgano-element chemistry

The aimed introduction of the polyfluoroorgano groups (4-C5F4N), C6F13C2H4, and C2F5 into methoxy group-containing boron electrophiles is reported. The new compounds obtained after transformations K[(4-C5F4N)BF3], (4-C5F4N)BF2, K[C6F13C2H4BF3], C6F13C2H4BF2, K[(C2F5)2B(OMe)2], and K[(C2F5)2BF2] were isolated and characterised. Additionally some of their precursors as there are Li(4-C5F4N), Li[(4-C5F4N)B(OMe)3], (4-C5F4N)B(OH)2 and the by-products Li[(4-C5F4N)2B(OMe)2], (4-C5F4N)2BOH, and K[(4-C5F4N)2BF2] are described. The usefulness of polyfluoroorganodifluoroboranes for introducing polyfluoroorgano groups into hypervalent FEF bonds is demonstrated by the synthesis of [C6F5(4-C5F4N)I][BF4] and [p-FC6H4(trans-CF3CFCF)I][BF4].