M. Tordeux et al., Isomerisation reaction of a gem-bis-trifluoromethyl olefin in a basic medium: a kinetic study, J FLUORINE, 111(2), 2001, pp. 147-152
The rearrangement of 5-phenyl-1,1,1-trifluoro-2-(trifluoromethyl)pent-2-ene
to 5-phenyl-1,1,1-trifluoro-2-(trifluoromethyl)pent-3-ene has been studied
by F-19 NMR in dimethylsulphoxide (DMSO). This isomerisation is catalysed
by a base such as triethylamine. It is apparent that the olefin is more sta
ble when the two trifluoromethyl groups are placed on a saturated carbon ra
ther than on a vinylic carbon. In the isomerisation process, the part of tr
iethylamine is to assist the intramolecular hydrogen transfer to give the m
ore stable isomer. (C) 2001 Elsevier Science B.V. All rights reserved.