Esters, vinyl

F.N. Tebbe (1978 [footnote 20]) and R.R. Schrock (1976) have shown that electrophilic titanium or tantalum ylides can alkylidenate the carbonyl group of esters. Vinyl ethers are obtained in high yields with Tebbe s reagent, p-chlorobis(ri -2,4-cyclopentadien-l-ylXdime-thylaluminum)- 4-methylenetitanium (S.H. Pine, 1980 A.G.M. Barrett, 1989). 

Vinylene shift Vinyl ester Vinyl ester resins... 

Organic peroxides are used in the polymer industry as thermal sources of free radicals. They are used primarily to initiate the polymerisation and copolymerisation of vinyl and diene monomers, eg, ethylene, vinyl chloride, styrene, acryUc acid and esters, methacrylic acid and esters, vinyl acetate, acrylonitrile, and butadiene (see Initiators). They ate also used to cute or cross-link resins, eg, unsaturated polyester—styrene blends, thermoplastics such as polyethylene, elastomers such as ethylene—propylene copolymers and terpolymers and ethylene—vinyl acetate copolymer, and mbbets such as siUcone mbbet and styrene-butadiene mbbet. 

Another important type of reactivity of palladium, namely oxidative addition to Pd(0), is the foundation for several methods of forming carbon-carbon bonds. Aryl126 and alkenyl127 halides react with alkenes in the presence of catalytic amounts of palladium to give net substitution of the halide by the alkenyl group. The reaction, known as the Heck reaction,128 is quite general and has been observed for simple alkenes, aryl-substituted alkenes, and substituted alkenes such as acrylate esters, vinyl ethers, and A-vinylamides.129... 

In contrast to the reactions of acyclic ADC compounds, good evidence exists for dipolar intermediates in the reaction of PTAD with enol esters. Vinyl acetate (54, R = Me) and PTAD react in dichloromethane at 60°C to give the triazole 55 via the dipolar intermediate 56.96 When the bulkier... 

Esters - vinyl ethers. The original publication (8, 83-84) mentioned that ethyl cetntc reacts with 1 to give ethyl isopropcnyl ether. More recent work1 has shown thul ihis conversion of esters to vinyl ethers is general and proceeds in high yields. The read ion rate is dramatically increased by the presence of donor ligands (THF, ( lhN). The solvent is benzene or toluene. Retone methylenation is possible, and Medially I lie rate is four limes Ihat of ester methylenation. Isolated yields are cited in Ihc examples. 

Versatic acid vinyl esters Vinyl ethers N-Vinylpyrrolidone Vinyl chloride Vinylidene chloride Semicrystalline polymers (2)... 

Coumarone-indene resins are sold under various trade names Cumar, Neville, Nevindene, Paradene Picoumaron. Numerous applications in industry include uses in plastics, protective coatings, adhesives, lacquers, and as plasticizers for cellulose esters vinyl resins Refs i) Beil 17, 56 [ 57.1 2) Kirk Othmer... 

Terpolymers made from two different olefins and CO are known. They were first described in Brubaker s initial patent and involved the free radical initiated terpolymerization of CO and C2H with another olefin such as propylene, isobutylene, butadiene, vinyl acetate, diethyl maleate or tetrafluoroethylene More recently, in another patent, Hammer has described the free radical initiated terpolymerization of CO and C2H with vinyl esters, vinyl ethers or methyl methacrylate 26Reaction temperatures of 180-200 °C and a combined pressure of 186 MPa were employed. Typically a CO QH4 olefin molar ratio of 10 65 25 was observed in the terpolymers. In other patents, Hammer 27,28) has described the formation of copolymers with pendant epoxy groups by the free radical initiated polymerization of CO, QH4, vinyl acetate and glycidyl methacrylate. Reaction conditions similar to those stated above were employed, and a typical CO C2H vinyl acetate glycidyl methacrylate molar ratio of 10 65 20 5 was observed in the product polymer. 

The formation of coagulum is observed in all types of emulsion polymers (i) synthetic rubber latexes such as butadiene-styrene, acrylonitrile-butadiene, and butadiene-styrene-vinyl pyridine copolymers as well as polybutadiene, polychloroprene, and polyisoprene (ii) coatings latexes such as styrene-butadiene, acrylate ester, vinyl acetate, vinyl chloride, and ethylene copolymers (iii) plastisol resins such as polyvinyl chloride (iv) specialty latexes such as polyethylene, polytetrafluoroethylene, and other fluorinated polymers (v) inverse latexes of polyacrylamide and other water-soluble polymers prepared by inverse emulsion polymerization. There are no major latex classes produced by emulsion polymerization that are completely free of coagulum formation during or after polymerization. 

Unsaturated vinyl esters for use in polymerization reactions are made by the esterification of olefins. The most important ones are vinyl esters vinyl acetate, vinyl chloride, acrylonitrile, and vinyl fluoride. The addition reaction may be carried out in either the liquid, vapor, or mixed phases, depending on the properties of the acid. Care must be taken to reduce the polymerization of the vinyl ester produced. 

They include vinyl acetate homopolymers and all copolymers in which vinyl acetate is the major constituent (50% or greater). The major PVAc copolymers are vinyl acetate-ethylene (VAE) and vinyl acetate-acrylic ester (vinyl acrylic). Vinyl acetate-versatic acid (vinyl versatate) and vinyl acetate- maleate are major PVAc copolymer emulsions used. 

Recent work176 shows that route A is more probable. Acetoacetic ester, vinyl ethers, and enamines react analogously with acetyl-benzoquinone. The reaction of acetoacetic ester probably goes via the enol form, as the reaction rate is solvent-dependent, i.e., it depends on the enol content176 ... 

Multiple bonds between the atoms in the molecules of conventional monomers may possess a relative excess or deficiency of electrons. In principle, only a few of these bond types exist nitrile, aldehyde, carbonyl, carboxyl, ester, vinyl and acetylene. In macromolecular chemistry, the reactions of anions with oxiranes, the amide and ester (in rings) and the siloxane bond are also of importance. 

Among the processes used for the formation of polyolefins, the longest-known but least selective one is free radical polymerization. A free radical species X produced e.g. by thermolysis of benzoyl peroxide or by photolysis of azabisisobutyronitrile (AIBN) - can react with the double bond of a vinyl derivative H2C=CHR to form a new radical of the type XCH2-CHR which can then add another H2C=CHR unit repetition of this process leads to polyolefin formation (Figure 2, top). This process works best for vinyl derivatives with unsaturated side groups, which provide resonance stabilization for an adjacent radical centre, e.g. with vinyl and acrylic esters, vinyl cyanides and vinyl chloride and with styrene and 1,3-dienes. It is extensively used in the emulsion polymerization of vinylic and acrylic derivatives and in the light-induced formation of photoresists for the nanofabrication of semiconductor chips and integrated electronic circuits. 

SYNS BUTYRIC ACID, VINYL ESTER VINYL BUTYRATE, INHIBITED (DOT) VINYLESTER KYSELINY MASELNE... 

Although not as extensively employed as vinyl esters, vinyl ethers find occasional use as intermediates in the conversion of ketones into alkenes. Once again, vinyl ethers can be generated regioselectively by kinetic or thermodynamic enolate generation and, therefore, offer another route by which ketones can be regioselectively replaced by alkenic double bonds. 

End-functionalized polymers with polymerizable groups such as double bonds and heterocycles of course provide macromonomers allyl, vinyl ester, vinyl ether, lactone, and epoxy are examples of such a category whose a-ends are not susceptible or have little susceptibility to metal-catalyzed radical polymerization. As discussed above, for example, allyl chloride and bromide (FI-33 and FI-34) are effective initiators to be used for styrene with CuCl and CuBr catalysts,161 while allyl compounds with remote halogens such as FI-35 and FI-36 allow the polymerization of methacrylates with high initiation effi-... 

The anion (26) of the isoquinoline Reissert compound (2) has been used in a Michael-type reaction. Thus, reaction of 26, generated with phenyllithium, with ethyl cinnamate and substituted cinnamates give rise to 63, dimethyl acetylenedicarboxylate yields 64, and 2- and 4-vinylpyridines give rise to 65. Use of cinnamonitrile in this sequence leads to the isolation of 66. The enol ester, vinyl acetate reacts with the isoquinoline Reissert compound in aqueous sodium hydroxide containing TEBA chloride to surprisingly give 67. ... 

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