Cyclopropanation of Vinyl Sulfides and Vinyl Sulfones

Cyclopropanation of vinyl sulfones and vinyl sulfides can be achieved by phase transfer catalysis where other cyclopropanation methods have failed.     

Syntheses of Vinyl Sulfoxide/Vinyl Acetate-Type Copolymers

The homopolymerization of a series of alkyl vinyl sulfoxides (CH₂[dbnd]CHSOR; R = CH₃ (MVSO), C₂H₅ (EVSO), t-C₄H₉ (BVSO)) and their copolymerization with vinyl acetate (VAc) with 2,2′-azobisisobutyronitrile (AIBN) as initiator at 60°C was attempted. MVSO was found to homopolymerize radically, but EVSO and BVSO were not. Poly-MVSO is soluble in chloroform, methanol, DMSO, and water, but insoluble in acetone and benzene. MVSO and EVSO were found to copolymerize with VAc, but BVSO was not. The copolymerization parameters obtained for both systems were as follows; r₁(MVSO) = 2.23, r₂ (VAc) = 0.09, and r₁(EVSO) = 3.40, r₂ (VAc) = 0.11, respectively. MVSO/vinyl alcohol (VA) copolymers were obtained through the saponification of MVSO/VAc copolymers by sodium hydroxide in methanol. The solubility of MVSO/VAc and of MVSO/VA copolymers toward various solvents was examined, and it was observed that the sulfoxide comonomer has a tendency to give amphiphilicit to poly(vinyl acetate) and poly(vinyl alcohol). The 24 mol% MVSO containing VAc copolymer is soluble in both benzene and water.     

Vinyl sulfones

Four neutral vinyl sulfones, two of which are paired with phosphonate groups, are described. The compounds are diisopropyl (2‐phenylethenylsulfonylmethyl)phosphonate, C₁₅H₂₃O₅PS, (I), diisopropyl {[2‐(7‐methoxy‐1,3‐benzodioxol‐5‐yl)ethenylsulfonyl]methylsulfonylmethyl}phosphonate, C₁₈H₂₇O₁₀PS₂, (II), bis(trans‐2‐phenylethenyl) sulfone, C₁₆H₁₄O₂S, (III), and bis(trans‐2‐phenylethenylsulfonyl)methane, C₁₇H₁₆O₄S₂, (IV). Their structures can be considered as highly functionalized mimics of mono‐, di‐ and triphosphates. These phosphate isosteres are currently of interest as agents for enzyme inhibition in both cancer and HIV therapy. All except one of the compounds has Z′ > 1. The lone exception is (IV), a disulfone with twofold crystallographic symmetry. Geometrically, the sulfone functionality is found to be a good mimic for phosphate. The principal effect of the vinyl group is to shorten the S—C(vinyl) distance relative to the S—CH₂ distance by ca 0.05 Å. The S—C—S and S—C—P backbones resemble the P—O—P backbone but are not identical because the S—C and P—C distances are longer than the P—O distance and the S—C—S and S—C—P angles are more acute than the P—O—P angle. No prior crystal structures of comparable compounds have been published.     

Cyclodimerizations and Copolymerizations of Vinyl Ketones with Vinyl Monomers

Stable high-molecular-weight polyacetals can be prepared from formaldehyde or from its trimer trioxane.     

General,Straightforward, and Atom-Economical Synthesis of Vinyl Triflimides

Vinyl triflimides were only accessible recently and their chemistry is yet to be discovered. Herein, we describe a general, straightforward and atom-economical synthesis of these materials from alkynes and triflimide. A vast array of terminal and internal alkynes with broad spectrum of functionalities could be employed to generate various di- and trisubstituted vinyl triflimides regiospecifically with high to specific stereoselectivity. Moreover, the protocol could be conducted on gram scale using terminal and internal alkynes. Preliminarily attempts to probe the unprecedented reactivity of vinyl triflimides revealed part of its chemical properties.     

Copolymerization of Diethyl Vinyl Phosphate with Vinyl Acetate and Acrylonitrile

Free radical-initiated copolymerization of diethyl vinyl phosphate (DEVPA) with vinyl acetate (VAc) and acrylonitrile (AN) was studied. The monomer reactivity ratios for the monomer pairs, determined at 60°C using benzoyl peroxide as an initiator, are: r₁(VAc) = 0.95, r₂(DEVPA) = 0.93; r₁(AN) = 6.6, r₂(DEVPA) = 0.049. The values of the Alfrey-Price constants, Q and e, for DEVPA were calculated to be 0.025 and 0.13, respectively, from the VAc system, and 0.026 and 0.14, respectively, from the AN/DEVPA pair. These results indicate that the general reactivity of DEVPA is almost the same as that of VAc and that the diethylphosphate group is a stronger electron-attracting group than the acetoxy group. The intrinsic viscosity and number-average molecular weight of copolymers decreased as their content of DEVPA units increased, indicating a high degree of chain transfer caused by DEVPA.     

Vinyl Chloride Peroxide Explosion in a Vinyl Chloride Recovery Plant

The formation of polymer peroxides by the addition of oxygen to unsaturated organic compounds was described for the first time by Staudinger, taking 1,l-diphenyl ethylene peroxide as an example [1]. In the meantime, numerous other polyperoxides have become known, among them the peroxides of acrylonitrile [2], dimethyl butadiene [3], chloroprene 141, methyl methacrylate 51, styrene 161, vinyl acetate [5], and vinyl chloride [7-10]. Because of the great significance of the aforementioned compounds as monomers in the production of plastic materials, the investigations centered on the influence of oxygen on the polymerization behavior of the monomers and on the properties of the polymers.     

Ionic Polymerization of α, α -Disubstituted Vinyl Monomers

Alkyl α-chloroacrylates and p-substituted α-methylstyrenes were investigated for the effect of polymerization conditions on tacticity, molecular weight, and distribution, and for the relationship between tacticity, glass temperature, and crystalline properties.     

Vinyl derivatives of 2, 5-diaryl-1, 3,4-oxadiazoles

Vinyl derivatives of 2, 5-diaryl-1, 3, 4-oxadiazoles have been synthesized and some of their physical properties have been studied.     

Vinyl phenyl telluride from metallic tellurium,acetylene, and iodobenzene

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, p. 200, January, 1988.     

Vinyl Triflimides—A Case of Assisted Vinyl Cation Formation

A new concept for selectivity control in carbocation‐driven reactions has been identified which allows for the chemo‐, regio‐, and stereoselective addition of nucleophiles to alkynes—assisted vinyl cation formation—enabled by a Li⁺‐based supramolecular framework. Mechanistic analysis of a model complex (Li₂NTf₂⁺?3 H₂O) confirms that solely the formation of a complex between the incoming nucleophile and the transition state of the alkyne protonation is responsible for the resulting selective N addition to the vinyl cation. Into the bargain, a general, operationally simple synthetic procedure to previously inaccessible vinyl triflimides is provided.     

Vinyl derivatives of 2, 5-diaryl-1, 3,4-oxadiazoles

Vinyl derivatives of 2, 5-diaryl-1, 3, 4-oxadiazoles have been synthesized and some of their physical properties have been studied.     

Copolymerization of Vinyl Cinnamate with Vinyl Acetate: Infrared Spectral Studies

Vinyl cinnamate (C) was synthesized and copolymerized with vinyl acetate (A) in benzene at 60° using benzoyl peroxide as initiator. Monomer distributions in the resulting copolymers were determined by the infrared spectral technique. A calibration curve was obtained for this purpose. Reactivity ratios as calculated by Kelen and Tüdös method were found to be rC= 1.401 ± 0.210, rA. = 0.043 ± 0.006.     

Corona-Poled Electrets Based on Vinyl Chloride/Vinyl Acetate Copolymer-Zinc White Composites

Electret properties of vinyl chloride/vinyl acetate copolymer and its composites with zinc oxide are studied.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 3, 2005, pp. 502–505.Original Russian Text Copyright © 2005 by Galikhanov, Deberdeev.     

Reactions of Vinyl Azides

This review is designed to demonstrate the versatility of vinyl azides in organic reactions. The reactive azide function is susceptible to thermolysis, photolysis, cycloadditions, and attack by nucleophiles and electrophiles. The neighboring double bond accentuates the reactivity of the azide function and provides additional intramolecular pathways for reaction. Last but not least, the presence of an appreciable electron density at the β-vinyl carbon makes this class of compounds comparable with enamines in their reactions with electrophiles and 1,3-dipoles.