19430-93-4Relevant articles and documents
Siloxane based syntheses of fluorous ethenes and their tandem Heck reactions with aryl iodides
Csapo, Agnes,Rabai, Jozsef
, p. 79 - 85,7 (2020/09/16)
Perfluoroalkyl-ethenes (RfnCHCH2, 6a-c; a, n = 4; b, n = 6; c, n = 8) were prepared in good isolated yields (67-89%) and high purity (GC assay > 98%) from various fluorinated organosilanes in fluoride-anion assisted protodesilylation reactions. The environmentally more benign 'KF/NEt3/H2O' reagent combination introduced here was found as an effective substitute for the commonly used tetrabutylammonium- fluoride trihydrate (TBAF·3H2O) as a fluoride source. Fluorous styrenes ((E)-RfnCHCHAr, 8) were then prepared in good isolated yields (58-93%/iodoarene) and purities (GC assay > 95%) with the Pd(0) catalyzed Heck coupling of iodoarenes (Ar-I, 7) and perfluoroalkyl-ethenes generated in situ by the fluoride assisted cleavage of (β-perfluoroalkyl- α-iodo-ethyl)-siloxane ([RfnCH2CH(I)SiMe 2]2O, 3) precursors in DMF solution at elevated temperatures. They are accessible by the one-pot reaction of dimethylvinylchlorosilane (CH2CHSiMe2Cl, 2) and perfluoroalkyl iodides (Rfn-I, 1) as we reported earlier. Similarly, the radical chain addition of C8F17I to CH 2CHSi(OMe)3 (9) gave (β-perfluorooctyl-α-iodo- ethyl)-trimethoxysilane ([C8F17CH2CH(I)]Si(OMe) 3, 10) in good yield, which then was reacted with silica gel in dry toluene to obtain an SiO2-bonded (perfluorooctyl)ethene surrogate [silica(O)3SiCH(I)CH2C8F17, 11]. The fluoride assisted cleavage of 11 and tandem Heck reaction with iodobenzene afforded the appropriate cross-coupled product (E)-C8F 17CHCHPh.
Impact of fluorine substituents on the rates of nucleophilic aliphatic substitution and β-elimination
Martinez, Henry,Rebeyrol, Adele,Nelms, Taylor B.,Dolbier Jr., William R.
experimental part, p. 167 - 175 (2012/03/27)
A measure of the quantitative effect of proximate fluorine substituents on the rates of SN2 and E2 reactions has been obtained through a study mainly of reactions of fluorinated n-alkyl bromides with weak base, strong nucleophile azide ion and strong base/nucleophile methoxide ion in the protic solvent methanol and the aprotic solvent, DMSO. The order of reactivity for SN2 reactions of azide in methanol at 50 °C was found to be: n-alkyl-Br > n-alkyl-CHFBr > n-perfluoroalkyl-CH2CH 2Br n-perfluoroalkyl-CH2Br > n-alkyl-CF2Br. Approximate relative rates of reaction were: 1, 0.20, 0.12, 1 × 10 -4, -5. The order of reactivity for E2 reactions was found to be: n-perfluoroalkyl-CH2CH2Br n-alkyl-CF2Br > n-alkyl-CHFBr > n-alkyl-Br. The approximate relative rates for reaction of methoxide in methanol at 50 °C were: 1100, 4.4, 1.9, 1.
Process for producing a polyfluoroalkyl (meth)acrylate
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Page 5; 6, (2008/06/13)
A process for producing a polyfluoroalkyl (meth)acrylate, which comprises isolating, from a reaction mixture containing a polyfluoroalkyl (meth)acrylate obtained by reacting a polyfluoroalkyl iodide of the formula CnF2n+1(CH2)mI (wherein n is an integer of from 2 to 7, and m is an integer of from 1 to 4) with a metal (meth)acrylate in tert-butanol, said polyfluoroalkyl (meth)acrylate by the following steps (1) to (3):(1) a step of taking out a crude liquid from the reaction mixture by solid-liquid separation;(2) a step of distilling the crude liquid to separate it into compound group A of compounds having a lower boiling point than the polyfluoroalkyl (meth)acrylate and compound group B of the polyfluoroalkyl (meth)acrylate and compounds having a higher boiling point than the polyfluoroalkyl (meth)acrylate; and(3) a step of distilling and purifying the polyfluoroalkyl (meth)acrylate from the compound group B in the presence of a polymerization inhibitor.
