Synthesis of a novel functional polymer immobilized platinum complex and its application in the catalytic hydrosilylation of 3,3,3-trifluoropropene with triethoxysilane

A novel polymer has been synthesized using 2-vinylpyridine as a functional monomer and allyl polyethylene glycol as a cross-linking agent, and platinum has been immobilized on this synthesized polymer. The resulting immobilized catalyst showed superior catalytic performance for the hydrosilylation of 3,3,3-trifluoropropene with triethoxysilane as compared to homogenous platinum catalyst, polystyrene-immobilized platinum or other hydrosilylation catalysts. The conversion of silane is about 100% and the maximum yield of β-adduct is 92.3% with slightly α-adduct. Furthermore, the catalyst showed sufficient stability that it could be reused three times without noticeable inactivation.     

Synthesis of α-trifluoromethylstyrene derivatives via Ni-catalyzed cross-coupling of 2-bromo-3,3,3-trifluoropropene and aryl Grignard reagents

The Ni-catalyzed cross-coupling of 2-bromo-3,3,3-trifluoropropene and aryl Grignard reagents was investigated. When NiCl₂(PPh₃)₂ was used as a catalyst, the highest yield of α-trifluoromethylstyrene (89%) from 2-bromo-3,3,3-trifluoropropene and PhMgBr was obtained in 1,3-dimethyl-2-imidazolidinone at 50 °C for 30 min. Various α-trifluoromethylstyrene derivatives could be produced in satisfactory yields by NiCl₂(PPh₃)₂-catalyzed coupling using aryl Grignard reagents.     

Convenient synthesis of 3,3,3-trifluoropropanoic acid by hydrolytic oxidation of 3,3,3-trifluoropropanal dimethyl acetal

A convenient and efficient method for preparing 3,3,3-trifluoropropanoic acid (1) is reported. The starting material is 1-chloro-3,3,3-trifluoropropene (2) that can be easily transformed into 3,3,3-trifluoropropanal dimethyl acetal (4) on treatment with methanol and KOH followed by acid-catalyzed addition of methanol. Direct transformation of 4 into 1 was efficiently achieved with 30% aqueous hydrogen peroxide (4.0 equiv.) in the presence of FeCl₃ (0.025 equiv.) and hydrochloric acid (0.5 equiv.).     

Radical telomerization of 3,3,3-trifluoropropene with diethyl hydrogen phosphonate: Characterization of the first telomeric adducts and assessment of the transfer constants

The radical telomerization of 3,3,3-trifluoropropene (TFP) with diethyl phosphate (or diethyl hydrogen phosphonate, DEHP) was investigated to synthesize fluorinated telomers bearing a phosphonate end-group, as H(TFP)_nP(O)(OEt)₂. Di-tert-butyl peroxide was the most efficient radical initiator. A careful structural study of typical TFP/DEHP telomers was performed by ¹H, ¹⁹F, and ³¹P nuclear magnetic resonance spectroscopies. These analytical methods allowed us to prove the selective addition of the phosphonyl radical onto the hydrogenated side of TFP, while the telomers containing more than two TFP units were composed of TFP isomers containing normal and reversed adducts. The kinetics of telomerization led to the assessment of the first four order transfer constants giving an infinite transfer constant of 0.75 at 140 °C for DEHP.     

由三氟异丙烯基溴化镁制备羧酸

以三氟丙烯和溴为原料加成制得1,2-二溴三氟丙烷,脱溴化氢得到2-溴三氟丙烯,再在一定条件下合成2-溴三氟丙烯的格氏试剂（三氟异丙烯基溴化镁）,与CO2反应最终生成1-溴-2-三氟甲基丙酸。 用碳酸钠溶液萃取的方法得到0.8 g产品,纯度为99.6%,收率为3.6%。 对产物进行了MS、IR、1H NMR和13C NMR等表征,并分析了主要副产物1,2-二氟丙二烯和2,3-二三氟甲基-1,3-丁二烯及其与未反应的2-溴三氟丙烯间的[2+2]或[2+4]环加成反应产物。 确定以2-溴三氟丙烯为原料经格氏反应制羧酸较好的反应条件为：以THF为溶剂,1,2-二溴乙烷作引发剂,制备格氏试剂温度为30 ℃,CO2与格氏试剂反应温度为0 ℃。     

Original fluorinated surfactants potentially non-bioaccumulable

This minireview updates non-exhaustive recent strategies of synthesis of original fluorosurfactants potentially non-bioaccumulable. Various strategies have been focused on (i) the preparation of CF₃–X–(CH₂)_n–SO₃Na (with X = O, C₆H₄O or N(CF₃) and n = 8–12), (ii) the oligomerization of hexafluoropropylene oxide (HFPO) to further synthesize oligo(HFPO)–CF(CF₃)CO–R_H (where R_H stands for an hydrophilic chain); (iii) the telomerization of vinylidene fluoride (VDF) with 1-iodopentafluoroethane or 1-iodononafluorobutane to produce C_nF_2n+1–(VDF)₂–CH₂CO₂R (n = 2 or 4, R = H or NH₄), (iv) the radical telomerization of 3,3,3-trifluoropropene (TFP) with isoperfluoropropyliodide or diethyl hydrogenophosphonate to prepare (CF₃)₂CF(TFP)_x–R_H or CF₃–CH₂–CH₂–(TFP)_y–P(O)(OH)₂, and (v) the radical cotelomerization of VDF and TFP, or their controlled radical copolymerization in the presence of (CF₃)₂CFI or a fluorinated xanthate. In most cases, the surface tensions versus the surfactant concentrations have been assessed. These above strategies led to various highly fluorinated (but yet not perfluorinated) telomers whose chemical changes enabled to obtain original surfactants as novel alternatives to perfluorooctanoic acid (PFOA), ammonium perfluorooctanoate (APFO), or perfluorooctylsulfonic acid (PFOS) regarded as bioaccumulable, persistent, and toxic.     

Preparation of two 1-phenyl-chlorofluoropropenes

1-Phenyl-2-chloro-3,3,3-trifluoropropene and 1-phenyl-l,2-dichloro- 3,3,3-trifluoropropene were prepared from 1-phenyl-3,3,3- -trifluoropropene by a chlorination-dehydrochlorination sequence. Intermediate 1-phenyl-l,2-dichloro-3,3,3-trifluoropropane and 1-phenyl-1,2,2-trichloro-3,3,3-trifluoropropane were also isolated. All compounds were characterised by elemental analysis, boiling points, ¹H and ¹⁹F NMR spectra.     

2-bromo-3,3,3-trifluoropropene: A facile trifluoromethylacetylene anion synthon

The introduction of trifluoromethylacetylene units into organic compounds has been further studied and extended. The direct reaction of two equivalents of Lithium Diisopropylamide with 2-bromo-3,3.3-trifluoropropene gave lithium trifluoromethylacetylide, the anion of which was trapped in greater than 90% overall yield with a variety of electrophiles.     

3,3,3-Trifluoropropan-1-OL and 3,3,3-trifluoropropanal

Acetoxymercuration of 3,3,3-trifluoropropene leads to 1-acetoxy-3,3,3- trifluoropropene which is hydrolysed to 3,3,3-trifluoropropanol, oxidation of which affords 3,3,3-trifluoropropanal.     

A convenient stereoselective synthesis of trifluoromethyl-substituted polyfunctionalized cyclopropane: synthesis of (+/-)-trans-trifluoronorcoronamic acid

Trifluoromethylated polyfunctionalized cyclopropanes were obtained in high stereoselectivity by reacting 2-bromo-3,3,3-trifluoropropene (BrTFP) with active methylenes. This novel method was further applied to the synthesis of (+/-)-trans-trifluoronorcoronamic acid.     

Studies on organic fluorine compounds. LIII. Preparation of functionalized trifluoromethylated compounds using 1-phenylsulfonyl-3,3,3-trifluoropropene

Reaction of 1-phenylsulfonul-3,3,3-trifluoropropene(1) with carbonyl-stabilized enolate anions smoothly proceeded to give the addition products(7) in good yield while with an alkyl-lithium or Grignard reagent the formation of the vinyl anion(8) was one of the reaction pathways. Reaction of 1 with the chiral nucleophiles(11, 16) was carried out to give the functionalized trifluoromethylated compounds(13, 7b) in 4-43% ee     

Stereoselective synthesis of trifluoromethyl-substituted 1,2-diamines by aza-Michael reaction with trans-3,3,3-trifluoro-1-nitropropene

Aza-Michael addition of optically pure 4-phenyl-2-oxazolidinone to 3,3,3-trifluoro-1-nitropropene proceeds smoothly at low temperature with a high yield. Diastereoselectivity of the addition depends on the base used and lithiated species proved to be highly efficient affording 92% de. Optically pure 1,2-diamino-3,3,3-trifluoropropane is prepared in 58% yield from the aza-Michael addition product through a three-step procedure.     

Novel method for the synthesis of (trifluoromethyl)oxirane

The reaction of 3,3,3-trifluoropropene with N-bromosuccinimide in acetic acid at 65—70 °C affords 3-acetoxy-2-bromo-1,1,1-trifluoropropane. When treated with an alkali, the latter is readily converted into (trifluoromethyl)oxirane.     

Nucleophilic addition of 3,3,3-trifluoropropynyllithium to d-glyceraldimine: Concise synthesis of both enantiomers of 5,5,5-trifluoronorvaline

3,3,3-Trifluoropropynyllithium, in situ generated by treatment of 2-bromo-3,3,3-trifluoro-1-propene 1 with 2.0 equiv. of LDA at −78 °C, was trapped with d-glyceraldimine 2 to give trifluoromethylated propargylic amine 4 in 55% yield. Starting from the key intermediate 4, Boc-protected (R)-5,5,5-trifluoronorvaline and (S)-5,5,5-trifluoronorvaline were concisely synthesized over three steps in 62% and 63% yield, respectively.     

High-temperature aging of fluoropolymers

Fluoropolymers including those of 3,3,3-trifluoropropene, 2,3,3,3-tetrafluoropropene, 3,3,4,4,5,5,5-heptafluoropentene-1, and their copolymers with tetrafluoroethylene, were aged in air and in its absence at 225 and 305°C. Intrinsic viscosities were measured before and after aging. Polymers of high tetrafluoroethylene content are most stable. In air the presence of tertiary hydrogens is associated with lowered stability but the presence of tetrafluoroethylene greatly mitigates this effect. Stress-relaxation studies in air of a vulcanizate of 3,3,3-trifluoropropene and tetrafluoroethylene cured by γ-rays indicate that the vulcanizate degrades much more rapidly than the untreated polymer.     

A domino approach of Heck coupling for the synthesis of β-trifluoromethylstyrenes

A domino approach of Heck coupling was used to synthesize β-trifluoromethylstyrene derivatives from iodoarenes and 1-iodo-3,3,3-trifluoropropane in moderate to good yields. This method avoids the use of low-boiling, gaseous reagents such as 3,3,3-trifluoropropene, and additives and phosphines in the catalytic system.     

Organophosphorus chemistry. Part 19. Free-radical addition of dialkyl phosphites to polyfluoro-olefins

An improved procedure for the peroxide-catalysed addition of dialkyl phosphites to tetrafluoroethylene is described, and the reactions of diethylphosphite with chlorotrifluoroethylene, 1,1-difluoroethylene,perfluoropropene, and 3,3,3-trifluoropropene have been investigated and found to yield diethyl 2-chloro-1,1,2-trifluoroethylphosphonate, diethyl 2,2-difluoroethylphosphonate, an 80:20 mixture of diethyl 2$\text{H}$-hexafluoro-$\text{n}$-propylphosphonate and diethyl 1$\text{H}$-hexafluoropropyl-2-phosphonate, and diethyl 3,3,3-trifluoropropyl-1-phosphonate, respectively.     

SYNTHESIS OF CF_3-SUBSTITUTED ENEDIYNES

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[3+2] Cycloaddition reactions of 1-substituted 3,3,3-trifluoropropenes with diazo compounds and nitrilimines – synthesis of pyrazolines and pyrazoles

Chemistry of Heterocyclic Compounds - 1,3-Dipolar cycloaddition reactions of 3,3,3-trifluoropropene derivatives containing a sulfonyl, sulfamide, or sulfoximine substituent in position 1 with...     

Reductive modification of difluoromethylene moiety in pentafluoropropionyl group

The reductive Mg-promoted defluorinative-silylation of 2,2,3,3,3-pentafluoropropiophenone readily produces the α-trifluoromethyl enol silyl ether, which then react with electrophiles to give a variety of 2-substituted-3,3,3-trifluoropropiophenones in excellent yields. The same protocol is applicable for the preparation of enol silyl ether of 3,3,3-trifluoropropiophenone. Fluoride ion catalyzed 1,2-desilylative-defluorination of 2,3,3,3-tetrafluoro-2-trimethylsilyloxypropiophenone provided 3,3,3-trifluoro-1-phenyl-1,2-propanedione in a good yield.