- The first example of sulfinatodehalogenation of 2,2,2-trifluoroethyl halides: A novel method for trifluoroethylation of alkenes and alkynes
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2,2,2-Trifluoroethylation of alkenes and alkynes with 2,2,2- trifluoroethyl iodide or bromide and sodium dithionite in DMSO or CH3CN/H2O can occur under mild conditions.
- Long, Zheng-Yu,Chen, Qing-Yun
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- Reversible and Irreversible ElcB Mechanisms in the Hydrolysis of 2,2,2-Trifluoroethanesulfonyl Chloride: Carbanion Intermediates in Aqueous Acid
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Hydrolysis of 2,2,2-trifluoroethanesulfonyl chloride (1) is shown to take place by way of the sulfene (CF3CH=SO2), formed by (a) an irreversible E1cB process over the pH range 1.8-5 with water acting as the carbanion-forming base in the lower pH range and hydroxide anion at higher pH, and (b) a reversible E1cB reaction in dilute acid.
- King, James F.,Gill, Manjinder Singh
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- The activation of carbon-chlorine bonds in per- and polyfluoroalkyl chlorides: DMSO-induced hydroperfluoroalkylation of alkenes and alkynes with sodium dithionite
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In DMSO, the addition reactions of perfluoroalkyl chlorides, R(F)Cl, to alkenes or alkynes can occur smoothly in the presence of 1.5 equiv of Na2S2O4 and NaHCO3 at 75-80 °C for 4-10 h to give the corresponding adducts (RCH2CH2RF or RCH = CHR(F)). Ethyl chlorofluoro- (1f), chlorodifluoro- (1g) acetates, even nonfluorinated compounds, such as ethyl dichloro- (1h), chloro- (1i) acetates, and chloroform (1j) can undergo the similar reaction. Treatment of ω-iodo (or chloro-) perfluoroalkyl chlorides [X(CF2)(n) Cl, n = 2, 4, X= I or Cl] with > 3 equiv of alkenes and Na2SO4 gives directly the symmetrically disubstituted alkanes (RCH2CH2)2(CF2)(n). The symmetrically and unsymmetrically disubstituted adducts RCH2CH2(CF2)(n)CH2CH2R' from ω-iodoperfluoroalkyl chlorides can be also obtained stepwise, i.e., through the further addition reactions of monoadducts, RCH2CH2(CF2)(n)Cl to olefins. However, for α,ω- dichloroperfluoroalkanes, the similarly stepwise reactions with an alkene is not clean, both bis-adducts and the corresponding ω-hydrides, RCH2CH2(CF2)(n)H as byproducts are also formed. In the absence of alkenes or alkynes, per- and polyfluoroalkyl chlorides can be converted to their sulfinate salts and sulfonyl chlorides.
- Long, Zheng-Yu,Chen, Qing-Yun
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p. 4775 - 4782
(2007/10/03)
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- Pyridine derived agents for cardiovascular diseases
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STR1 Compounds of formula (I) or a biolabile ester thereof, or a pharmaceutically acceptable salt of either, wherein Rl, R2, R3 and R4 are each independently selected from H or C1 -C4 alkyl; R5 is (CH2)m SO2 R6, (CH2)m NHSO2 R6 or (CH2)m NHCOR7 ; R6 and R7 are C1 -C6 alkyl, C1 -C3 perfluoroalkyl(CH2)n, C3 -C6 cycloalkyl(CH2)n, aryl(CH2)n or heteroaryl(CH2)n ; or R6 is NR8 R9 ; R8 is H or C1 -C4 alkyl; R9 is C1 -C6 alkyl, C3 -C6 cycloalkyl(CH2)n, aryl(CH2)n or heteroaryl(CH2)n ; or R8 and R9 together with the nitrogen atom to which they are attached form a 5- to 7-membered heterocyclic ring which may optionally incorporate a carbon-carbon double bond or a further hetero atom linkage selected from O, S, NH, N(C1 -C4 alkyl) and N(C1 -C5 alkanoyl), and which may optionally be substituted with one to three substituents each independently selected from C1 -C4 alkyl and C1 -C4 alkoxy, and which may optionally be benzo-fused; X is CH2, CHCH3, C(OH)CH3, C=CH2 or O; m is 0 or 1; n is 0, 1, 2 or 3; and Het is 3- or 4-pyridyl or 1-imidazolyl; with the proviso that when Het is 1-imidazolyl then X is CH2 or CHCH3, are combined thromboxane A2 synthetase inhibitors and thromboxane A2 /endoperoxide antagonists of utility in the treatment of disease conditions in which thromboxane A2 is a causative agent.
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- Amine-Stabilized Sulfenes, their Synthesis and Structure
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The synthesis of quinuclidine-stabilized sulfene of the type XCH2-SO2-C(Y)=SO2- + (5a-d), whereas the corresponding methyl quinuclidinium salts (6a, b) are formed under methanolysis.
- Hartwig, Uwe,Pritzkow, Hans,Sundermeyer, Wolfgang
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p. 1435 - 1440
(2007/10/02)
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- SYNTHESIS OF THREE PARTIALLY FLUORINATED ALKANESULFONIC ACIDS AS POTENTIAL FUEL-CELL ELECTROLYTES.
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The simple and effective syntheses of CH//2FCH//2SO//3H, CF//3CH//2SO//3H, AND CHF//2CF//2CH//2SO//3H have been achieved with 18. 8%, 34. 1%, and 33. 7% overall yields. The low molecuar weight partially fluorinated alkanesulfonic acids containing alpha -methylene groups can be prepared from the p-toluenesulfonates of the corresponding alcohols, via a reaction with benzyl mercaptan, followed by an oxidative chlorination of the resulting sulfides, with subsequent hydrolysis of the sulfonyl chloride. The reaction of partially fluorinated alkyl halides with sodium sulfite (Strecker's method) proved to be inefficient (very low yields) and unreliable. The sulfonate salts formed are difficult to recover and purify.
- Bunyagidj,Piotrowska,Aldridge
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p. 344 - 346
(2007/10/02)
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