- Fluorosulfates of hexafluoroisobutylene and its higher homologs
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Hexafluoroisobutylene and its higher homologs are easily reacted with SO3 to give fluorosulfates of the formula CH2═C(R)CF2OSO2F, wherein R is a linear, branched or cyclic fluoroalkyl group comprised of 1 to 10 carbon atoms and may contain ether oxygen. These compounds react under mild conditions with many nucleophiles to give CH2═C(R)CF2X, where X is derived from the nucleophile. This reaction provides a route to many substituted hexafluoroisobutylenes, which copolymerize easily with other fluoro- and hydrocarbon monomers such as vinylidene fluoride and ethylene.
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- Alkoxycarbonylation of 3,3,3-Trifluoropropyne: An Intriguing Reaction to Prepare Trifluoromethyl-Substituted Unsaturated Acid Derivatives
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The addition of CO and methanol to 3,3,3-trifluoropropyne is catalysed by Pd(OAc)2 in the presence of (6-methylpyrid-2-yl)diphenylphosphine and CH3SO3H. The main products of the reaction are the methyl esters of 2-(trifluoromethyl)propenoic acid 1 and of 3-(trifluoromethyl)propenoic acid 2 (4,4,4-trifluorobut-2-enoic acid). The regioselectivity of the reaction can be controlled to a great extent by a suitable choice of the composition of the catalytic system and the reaction conditions. Thus, 1 can be obtained in 93% yield by using P(CO) = 20 atm and high ligand/Pd and acid/Pd ratios. On the other hand, selectivity up to 85% in 2 can be achieved using P(CO) = 80 atm and a low ligand/Pd ratio together with a high acid/Pd ratio. The reaction mechanism is also discussed.
- Scrivanti,Beghetto,Matteoli
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p. 543 - 547
(2007/10/03)
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- Studies on the preparation of 2-(trifluoromethyl)acrylic acid and its esters from 3,3,3-trifluoropropene via hydrocarbonylation reactions
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The synthesis of methyl α-(trifluoromethyl)acrylate (MTFMA) has been carried out in three steps starting from commercially available 3,3,3,-trifluoropropene; this route involving the cobalt-catalyzed carbonylation of 2-bromo-3,3,3-trifluoropropene (2-Br-TFP) under very mild reaction conditions, gave only about 30% yield of the desired methyl ester. 2-(Trifluoromethyl)propanal, available in 90% yield by rhodium catalyzed hydroformylation of 3,3,3-trifluoropropene, proved to be an interesting starting product for the preparation of MTFMA: while the synthetic route involving the α-halogenation of 2-(trifluoromethyl)propanoic acid (TFMPA) failed to give any results, the reaction scheme based on the α-selenenylation of the above aldehyde followed by H2O2-oxidation afforded 68% yield of 2-(trifluoromethyl)acrylic acid (TFMAA).
- Botteghi, Carlo,Lando, Claudia,Matteoli, Ugo,Paganelli, Stefano,Menchi, Gloria
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- FACILE SYNTHESES OF FLUORINE-CONTAINING α,β-UNSATURATED ACIDS AND ESTERS FROM 2-TRIFLUOROMETHYLACRYLIC ACID
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Various types of fluorine-containing α,β-unsaturated acids and their esters were synthesized from 2-trifluoromethylacrylic acid as a sole starting material.
- Fuchikami, Takamasa,Shibata, Yoshiko,Suzuki, Yasuyuki
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p. 3173 - 3176
(2007/10/02)
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