Telomerization of vinylidene fluoride with alkyl (or aryl) trifluoromethanethiosulfonates

The photochemical‐induced telomerization of vinylidene fluoride (VDF) with cyclohexyl (or phenyl) trifluoromethanethiosulfonate (CF₃SO₂SR), leading to CF₃(VDF)_nSR telomers, where R stands for cyclohexyl or phenyl, is presented. These sulfurated transfer agents were synthesized by the reaction between sodium triflinate (CF₃SO₂Na) and disulfide in the presence of bromine. ¹⁹F NMR spectroscopy enabled an assessment of the average degrees of telomerization (DP_n) of these telomers with a neat CF₃ end group as the label. These DP_n values increased for higher [VDF]₀/[CF₃SO₂SR]₀ initial molar ratios. Interestingly, the normal/reversed ratio of VDF units in these telomers was low. Finally, the cotelomerization of VDF and hexafluoropropylene with these transfer agents was successfully achieved, leading to original ω‐CF₃ fluoroelastomers, the thermal properties of which were investigated. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4538–4549, 2002     

Synthesis of alkyl or aryl pyridazinyl ethers

This paper presents the synthesis of some alkyl or aryl pyridazinyl ethers from 2‐alkyl‐4‐halo‐5‐hydroxy‐and 2‐alkyl‐4,5‐dichloropyridazin‐3(2H)‐ones or 3,6‐dichloropyridazine. Reaction of 2‐alkyl‐4‐halo‐5‐hydroxypyridazin‐3(2H)‐ones 1 with 1,2‐dibromoethane or 1,3‐dibromopropane gave the corresponding monopyridazin‐5‐yl ethers 2 and α,ω‐[di(pyridazin‐5‐oxy)]alkanes 3 . Treatment of 4 with 4‐substituted‐phenol afforded 5‐(4‐substituted‐phenoxy)‐2‐(4‐substituted‐phenoxymethyl) derivatives 5 . Reaction of 2‐alkyl‐4,5‐dichloro derivatives 7 with 1 gave the corresponding di(pyridazin‐5‐yl) ethers 8 in good yields. Compound 10 was reacted with catechol to give monopyridazin‐3‐yl ether 11 and/or di(pyridazin‐3‐yl) ether 12 . Also we described the results for the reaction of 2‐alkyl‐4‐chloro‐5‐(4‐substituted‐phenoxy)pyridazin‐3(2H)‐ones with nucleophiles.     

Synthesis and structures of alkyl (aryl) benzazolylazoketoximes

Alkyl(aryl)benzazolylazoketoximes were obtained by nitrosation of the hydrazones of alkyl- and aryl-substituted aldehydes by means of n-amyl nitrite. On the basis of data from IR and PMR spectroscopy it was concluded that the synthesized compounds exist in the oxime form. Their acid ionization constants were determined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1101–1105, August, 1980.     

Synthesis of tetrakis(alkyl,aryl)thioethylenes

Conclusions A convenient method was developed for the synthesis of tetrakis(alkyl,aryl)thioethylenes by reacting tetrachloroethylene with thiolates in aprotic solvents as the medium.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 467–470, February, 1979.     

Synthesis of poly(alkyl aryl ether) dendrimers

Poly(alkyl aryl ether) dendrimers of up to four generations composed of a phloroglucinol core, branching components, and pentamethylene spacers are synthesized by a divergent growth methodology. A repetitive synthetic sequence of phenolic O-alkylation and O-benzyl deprotection reactions are adopted for the synthesis of these dendrimers. The peripheries of the dendrimers contain 6, 12, 24, and 48 phenolic hydroxyl groups, either in the protected or unprotected form, for the first, second, third, and fourth generations, respectively. Because of the presence of hydrophilic exterior and relatively hydrophobic interior regions, alkaline aqueous solutions of these dendrimers are able to solubilize an otherwise insoluble pyrene molecule and these supramolecular complexes precipitate upon neutralization of the aqueous solutions.     

Silver-catalyzed cross-coupling reactions of alkyl bromides with alkyl or aryl Grignard reagents

Treatment of secondary or tertiary alkyl bromides with alkyl Grignard reagents in the presence of catalytic amounts of silver bromide and potassium fluoride in CH₂Cl₂ afforded the corresponding cross-coupling products in reasonable yields. Moreover, silver showed catalytic activity for the cross-coupling reactions of alkyl bromides with aryl Grignard reagents.     

Investigation of the addition of dialkyl(aryl)phosphine oxides to alkyl(aryl)vinyldialkoxysilanes

Conclusions Alkyl(aryl){2-[dialkyl(aryl)phosphoryl]ethyl}dialkoxysilanes were obtained as a result of addition of dialkyl(aryl)phosphine oxides to alkyl(aryl)vinyldialkoxysilanes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 183–186, January, 1985.     

Electrophilic substitution of diazonium salts in 2-amino-4-(alkyl or aryl)oxazoles

Aryl diazonium fluoborates react readily with 2-amino-4-alkyloxazoles and 2-amino-4-aryloxazoles under mild conditions. The products are the corresponding 5-arylazo derivatives formed, in 44-98% yield free from side products.     

Synthesis of diphenyl[alkyl(aryl)trimethylsiioxymethyl]phosphines

A series of previously unknown diphenyl[alkyl(aryl)trimethylsiloxymethyl]phosphines was prepared by the reaction of diphenyl(trimethylsilyl)phosphine with carbonyl compounds. The first complexes of these ligands with palladium chloride were prepared.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 754–756, April, 1994.