4.5- dialkyl-2-vinyl

Cp (C5Me4CH2CH2NMe2)TiCl2 (Cp = Cp, Cp ) are obtained by oxidation of the Ti(m) compounds Cp (C5Me4CH2CH2NMe2)TiCl with PbCl2. The molecular structure of the Cp derivative has been determined by X-ray diffraction, which reveals a non-coordinated NMe2 group. The dichloro compounds have been converted to a series of dialkyl, vinyl, titanacyclobutane, and fulvene complexes by the appropriate reactions (Scheme 531 Section 4.05.4.2.4).1093... 

The halohydroxylation method has been developed for exploiting the reactivity of the double bond present in dialkyl vinyl- and propenylphosphonates. Preparation of the halohydrins of diethyl vinylphosphonate failed using NBS or NBA. Treatment of diethyl vinylphosphonate on large scale with NaOCl or NaOBr in aqueous medium at pH < 3 gives the halohydrins with the hydroxyl group in the P-position (anti-Markovnikoff addition) with 95% or 65-85% purity, respectively (Scheme 4.9). As a consequence of the acid conditions, the preparation of halohydrins is generally accompanied by the formation of undesired diethyl 1,2-dihalogenophosphonates. ... 

Perkow reaction.1 Perkow2 noted that a-halo aldehydes and ketones react with trialkyl phosphites to give dialkyl vinyl phosphates ... 

In 1952, Perkow reported (242) that a-haloaldehydes did not react with trialkyl phosphites according to the Michaelis-Arbuzov reaction, although this had been repeatedly reported, but that a new type of reaction occurred, yielding dialkyl vinyl phosphates isomeric with the expected phosphonates. 

In order to improve the synthesis of dialkyl vinyl ether phosphonates, transetherification has heen used between the hydrojgrl compound and the vinyl ether. In this case, the phosphonate group is introduced by the hydro>yl compound. Transetherification efficiently occurs when catalyzed by mercury or palladium salts.Watanabe showed that with an excess of alcohol and with about 3% of mercury(II) acetate, they were able to obtain a wide range of functional vinyl ethers, according to the mechanism shown in Scheme 3.7. 

The monohydroboration of terminal alkynes with dicyclohexylborane, disiam-ylborane, catecholborane, and dimesitylborane, and complexes of dihaloboranes and 9-BBN provides the simple and efficient route to fra s-vinylboranes [1,2]. Unlike other dialkyl(vinyl)boranes, vinyl-9-BBN derivatives exhibit remarkable stability [3, 4]. However, with 1 1 stoichiometry of terminal alkyne 9-BBN, 9-BBN adds twice to give a significant amount of diboryl adduct (Eq. 5.19) from which boron stabilized carbanion can be made [5, 6]. The partial solution to dihydroboration is achieved either by employing 100% excess of the alkyne [3] or using silylated derivatives [4e, h]. 

Additives acting on the pour point also modify the crystal size and, in addition, decrease the cohesive forces between crystals, allowing flow at lower temperatures. These additives are also copolymers containing vinyl esters, alkyl acrylates, or alkyl fumarates. In addition, formulations containing surfactants, such as the amides or fatty acid salts and long-chain dialkyl-amines, have an effect both on the cold filter plugging point and the pour point. 

In cationic polymerization the active species is the ion which is formed by the addition of a proton from the initiator system to a monomer. For vinyl monomers the type of substituents which promote this type of polymerization are those which are electron supplying, like alkyl, 1,1-dialkyl, aryl, and alkoxy. Isobutylene and a-methyl styrene are examples of monomers which have been polymerized via cationic intermediates. 

Because high temperatures are required to decompose diaLkyl peroxides at useful rates, P-scission of the resulting alkoxy radicals is more rapid and more extensive than for most other peroxide types. When methyl radicals are produced from alkoxy radicals, the diaLkyl peroxide precursors are very good initiators for cross-linking, grafting, and degradation reactions. When higher alkyl radicals such as ethyl radicals are produced, the diaLkyl peroxides are useful in vinyl monomer polymerizations. 

Reaction conditions depend on the reactants and usually involve acid or base catalysis. Examples of X include sulfate, acid sulfate, alkane- or arenesulfonate, chloride, bromide, hydroxyl, alkoxide, perchlorate, etc. RX can also be an alkyl orthoformate or alkyl carboxylate. The reaction of cycHc alkylating agents, eg, epoxides and a2iridines, with sodium or potassium salts of alkyl hydroperoxides also promotes formation of dialkyl peroxides (44,66). Olefinic alkylating agents include acycHc and cycHc olefinic hydrocarbons, vinyl and isopropenyl ethers, enamines, A[-vinylamides, vinyl sulfonates, divinyl sulfone, and a, P-unsaturated compounds, eg, methyl acrylate, mesityl oxide, acrylamide, and acrylonitrile (44,66). 

Such copolymers of oxygen have been prepared from styrene, a-methylstyrene, indene, ketenes, butadiene, isoprene, l,l-diphen5iethylene, methyl methacrjiate, methyl acrylate, acrylonitrile, and vinyl chloride (44,66,109). 1,3-Dienes, such as butadiene, yield randomly distributed 1,2- and 1,4-copolymers. Oxygen pressure and olefin stmcture are important factors in these reactions for example, other products, eg, carbonyl compounds, epoxides, etc, can form at low oxygen pressures. Polymers possessing dialkyl peroxide moieties in the polymer backbone have also been prepared by base-catalyzed condensations of di(hydroxy-/ f2 -alkyl) peroxides with dibasic acid chlorides or bis(chloroformates) (110). 

A number of synthetic polymers having the abHity to control filtration rates at high temperature and in the presence of calcium and magnesium have also been developed (88). Such materials include vinyl sulfonate—vinyl amide copolymers (89,90), a copolymer of AMPS and A/,A/-dialkyl (meth) acrylamide (91) and a sulfonated hydroxylated polymer (92). AppHcation levels for these materials range from 5 to 18 kg/m (2—6 lb /bbl). Sulfonated asphalt is also used for high temperature filtration control. 

Formation of Sulfides. Thiols react readily with alkenes under the same types of conditions used to manufacture thiols. In this way, dialkyl sulfides and mixed alkyl sulfides can be produced. Sulfides are a principal by-product of thiol production. Mixed sulfides can be formed by the reaction of the thiol using a suitable starting material, as shown in equations 21, 22, and 23. Vinyl sulfides can be produced by the reaction of alkynes with thiols (38). 

Where X is Br or Q, the free acids may be obtained by acidification of the alkaline solution, but where X is I, the acids must be isolated as salts to avoid reduction of the arsonic acids by HI. Rather than using alkyl haUdes, alkyl or dialkyl sulfates or alkyl arenesulfonates can be used. Primary alkyl haUdes react rapidly and smoothly, secondary haUdes react only slowly, whereas tertiary haUdes do not give arsonic acids. AHyl haUdes undergo the Meyer reaction, but vinyl hahdes do not. Substituted alkyl haUdes can be used eg, ethylene chlorohydrin gives 2-hydroxyethylarsonic acid [65423-87-2], C2H2ASO4. Arsinic acids, R2AsO(OH), are also readily prepared by substituting an alkaU metal arsonite, RAs(OM)2, for sodium arsenite ... 

Imidazolinium perchlorate, 4-hydroxy-2,5,5-trimethyl-4-phenyl-synthesis, S, 487 Imidazolinium salts antistatic agents, 1, 409 Imidazolinium salts, 1-vinyl-polymerization, 1, 280 Imidazolin-2-one, 1-cyano-synthesis, S, 482 Imidazolin-2-one, 4,5-dialkyl-synthesis, S, 491 Imidazolin-2-one, 4,5-diaryl-bromination, S, 399-400 lmidazolin-2-one, 4,5-di( p-bromophenyl)-reactions... 

Whilst vinyl acetate is reluctant to copolymerise it is in fact usually used today in copolymers. Two of particular interest to the plastics industry are ethylene-vinyl acetate (Chapter 11) and vinyl chloride-vinyl acetate copolymers (Chapter 12). In surface coatings internal plasticisation to bring the Tg to below ambient temperatures and thus facilitate film forming is achieved by the use of ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate and dialkyl maleates and fumarates. 

As alkylating agents may for example be used alkyl halides, dialkyl sulfates, alkyl sulfonates and epoxides. Aryl halides and vinylic halides do not react. 

Dialkyl cuprates may also be added to aryl vinyl sulphoxides and the resulting a-sulphinyl carbanions can be treated with various electrophiles such as aldehydes, ketones and alkyl halides (equation 350)643. 

The sulfosuccinates must be individually evaluated under varying conditions to obtain optimum results. For example, disodium laureth-5 sulfosuccinate (DLFS) is excellent for finely dispersed lattices styrene-homo- and copolymers, styrene-acrylate copolymers, acrylate-homo- and copolymers, and vinyl acetate-homo-and copolymers. DLFS is used in a concentration (related to monomer) of 3-5%. Table 19 shows possible application areas of dialkyl sulfosuccinates. 

Recently, anchimeric assistance was also reported in the solvolysis of dialkyl-j3-thiovinyl sulfonates (184). In particular, vinyl ester 221 reacts 3.8 X 10 times faster and vinyl ester 222, 4.2 x 10 times faster, respectively, than model compound 223 in 9 1 CH3N03 CH3 0H at 25°. The large anchimeric effects, 10 to 10, in the solvolysis of dialkyl- 3-thiovinyl sulfonates... 

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