Fluorination of C6F5MX3 compounds (MSi, Ge; XF, Cl, Br, Alk) with xenon difluoride and XeF+ Y- salts

Preparation of polyfluorinated cycloalk-1-enyl-, alk-1-enyl-, and alkyliodine tetrafluorides using XeF2 in the presence of appropriate Lewis acids as fluorooxidant

“…The Lewis acid-catalysed fluorine addition to C 6 F 5 IF 4 and C 6 HF 4 IF 4 using xenon difluoride occurs in the same way as the corresponding addition reactions to pentafluoro-(C 6 F 5 R) and tetrafluorobenzene derivatives (C 6 HF 4 R) [6][7][8]. This means the same or a closely related mechanism of reaction.…”

“…Alternatively, the fluorination of the pentafluorophenyl group can run parallel to the addition of fluorine to iodine. To get more insight into the fluorinating process, we studied the reaction of xenon difluoride with pentafluorophenyliodine difluoride (6) and with iodopentafluorobenzene (5) in the presence of the weak Lewis acid boron trifluoride in the inert solvent 1,1,1,3,3-pentafluorobutane (PFB) [11].…”

“…After stirring at 20 8C for 2 h the mother liquor contained perfluorocyclohexa-1,4-dienyliodine difluoride (7), C 6 F 5 IF 4 (1), and dienes C 6 F 7 IF 4 (2, 3) beside unchanged pentafluorophenyliodine difluoride (6). The subsequent addition of XeF 2 (four equivalents) caused dissolution of the precipitate and finally perfluorinated cyclohexadienyliodine tetrafluoride 2 and cyclohexenyliodine tetrafluoride 4 (70:30) were obtained in quantitative yield (Scheme 3).…”

“…Under similar conditions, the reaction of either C 6 F 5 IF 4 or C 6 F 5 I with ClF 3 in large excess gave C 6 ClF 8 IF 4 and C 6 Cl 2 F 7 IF 4 (presumably, polyfluorinated cyclohexenyliodine tetrafluorides), the constitution of which was not studied [2]. On the other hand, heating of molten C 6 F 5 IF 2 with xenon difluoride at 60-65 8C for 3 h led to the quantitative formation of C 6 to the pentafluorophenyl group [3]. In the presence of Lewis acids the fluorinating ability of xenon difluoride is raised strongly caused by either the polarisation of the xenonfluorine bond in case of a relatively weak fluoride anion acceptor or the complete ionisation to [FXe][Y] under the action of a strong fluoride anion acceptor.…”

“…In the presence of Lewis acids the fluorinating ability of xenon difluoride is raised strongly caused by either the polarisation of the xenonfluorine bond in case of a relatively weak fluoride anion acceptor or the complete ionisation to [FXe][Y] under the action of a strong fluoride anion acceptor. Previously, we have successfully employed xenon difluoride in the presence of Lewis acids (aHF, BF 3 , SbF 5 ) to convert polyfluoroarenes bearing either electron donating (SiMe 3 , SiMe 2 F, SiMe 2 C 6 F 5 , GeEt 3 ) or electron withdrawing (F, Cl, Br, NO 2 , CN, CF 3 , SiF 3 , GeF 3 , Xe + ) substituents into the corresponding polyfluorocycloalkenyl derivatives [4][5][6][7][8][9]. In our present investigation we use this kind of oxidative fluorinating reaction for the preparation of polyfluoroorganoiodine(V) tetrafluorides [10].…”