Telomerization Of Vinyl Chloride Research Articles

Telomerization of Vinyl Chloride with Chloroform Initiated by Ferrous Chloride-Dimethylacetamide under Ultrasonic Conditions

Telomerization of vinyl chloride with chloroform was investigated using ferrous chloride-dimethylacetamide system, and 42.1% yield, more than four times the one reported before, was achieved. The addition of ultrasound further improved the reaction and yield was raised to 51.9% with trace byproducts at highly reduced reaction time and temperature. Ferrous chloride-dimethylacetamide under ultrasonic irradiation acts as a very efficient catalyst system for the 1 : 1 telomerization.

Radical-type addition of benzyl bromide to vinyl chloride: the kinetics and activation energy of the process

Radical telomerization of vinyl chloride with benzyl bromide and the competitive reaction of benzyl bromide with vinyl chloride and trimethylvinylsilane have been studied. The relative rate constant for the addition of C6H5C · H2 to vinyl chloride,k rel (with respect to trimethylvinylsilane), is close to unity, whereas the activation energy of the addition of C6H5C.H2 to vinyl chloride is considerably lower (by 7 kcal mol−1) than in the reaction involving trimethylvinylsilane. The possible fragmentation of the radical-adduct C6H5CH2CH2C.HCl was suggested as one of the possible reasons of underestimation ofk rel. The activation energy was estimated by the MPDO/3 method.

Relative kinetics of the radical telomerization of vinyl chloride with carbon tetrabromide and dichlorodibromomethane

1. Based on data obtained concerning the relative, kinetics of telomerization of vinyl chloride with CX2Br2 (X=Br, Cl), the radicals CBr3CH2CHCl and CCl22BrCH2ĊHCl are approximately an order of magnitude more reactive (faster) at chain transfer to an electrophilic telogen CX2Br2 compared to addition to vinyl chloride. 2. Tetrabromomethane is more reactive toward chain transfer with respect to telomerization with vinyl chloride than is dichlorodibromomethane.

Telomerization of vinyl chloride by methyl methoxyacetate

The telomerization of vinyl chloride by methyl methoxyacetate proceeds due to cleavage of the α-C-H and methoxy group C-H bonds in the telogen and is accompanied by rearrangement of the radicals with 1,5-hydrogen migration.

Correlation between the electron affinity of bromine-containing polyhalomethanes and individual chain transfer constants in the telomerization of vinyl chloride

Correlation between the electron affinity of bromine-containing polyhalomethanes and individual chain transfer constants in the telomerization of vinyl chloride

ChemInform Abstract: Telomerization of Vinyl Chloride with Dichloroacetoacetic Ester and Ethyltrichloroacetate.

AbstractDie Eisenpentacarbonyl‐katalysierte Umsetzung von Dichloracetessigsäureester (I) mit Vinylchlorid (II) führt zu einem Gemisch der Produkte (III)‐(V).

Telomerization of vinyl chloride with ethyl dichloroacetoacetate and ethyl trichloroacetate

1. Ethyl dichloroacetoacetate and vinyl chloride in the presence of Fe(CO)5-DMFA form the adduct CH3COCCl(CH2CHCl2)COOC2H5 and telomer (CHCl2CH2)2CClCOOC2H5, while formation of the telomer is accompanied by elimination of the COCH3 group. 2. As a result of the reaction of ethyl trichloroacetate with vinyl chloride, initiated by Fe(CO)5-DMFA, the adduct CHCl2CH2CCl2COOC2H5 and mixture of telomers (CHCl2CH2)2CClCOOC2H5 and Cl(CHClCH2)2CCl2COOC2H5 are formed.

EPR determination of rate constant of splitting chlorine from CCl4 by telomeric radicals CCl3(CH2CHCl)n� (n=1,2) and their addition to vinyl chloride and nitrosodurene

1. Rate constants of splitting the chlorine atom from CCl4 by the CCl3(CH2CHCl)n· radicals and addition of these radicals to vinyl chloride and nitrosodurene at 40°C were determined by the EPR method. 2. It was shown that in the telomerization of vinyl chloride with CCl4, the changes in the individual chain transfer constants are due to changes in the values of both the chain transfer and chain propagation rate constants.

Homolytic addition and telomerization reactions accompanied by the disproportionation of adducts

1. The telomerization of vinyl chloride by methylene bromide initiated by the Fe(CO)5+DMFA system yields CH2BrCH2CHCl2, CH2BrCH2CHBr2, CH2BrCH2CHClCH2CHCl2, and CH2BrCH2CHBrCH2CHClBr, which form as a result of the disproportionation of the adduct, along with the usual telomers BrCH2(CH2CHCl)nBr (n=1 and 2). 2. Disproportionation of the adduct under the action of coordination initiators has been noted for the first time in telomerization in the example of compounds with a CClBr group, which yield compounds with CCl2 and CBr2 groups. 3. The addition of CCl2 to CH4=CBrCH3 initiated by the Fe(CO)5-DMFA system also takes place with disproportionation of the adduct and yields a mixture of CCl3CH2CClBrCH3, CCl3CH2CCl2CH3, and CCl3CH2CBr2CH3.

Telomerization of vinyl chloride with iododifluoromethanesulfonyl fluoride

1. The products of the radical telomerization of vinyl chloride with FSO2CF2I, i.e., the telomers FSO2CF2(CH2CHCl)nI with n=1–3, have been isolated. 2. At 90°C ordinary telomerization is accompanied to a considerable extent by stepwise telomerization; however, at 60°C the contribution of the secondary reactions to the formation of the homologous telomers is insignificant. 3. The partial chain-transfer constants to FSO2CF2I for FSO2CF2(CH2CHCl)n (n=1–3) radicals at 60°C have been determined.

Telomerization of vinyl chloride by benzyl chloride

The systems Fe(CO)5 + hexamethylphosphotriamide and Fe(CO)5 + DMF are efficient initiators for the telomerization of vinyl chloride by benzyl chloride involving the C-Cl bond of the benzyl chloride, in which connection both the conversion of the telogen and yield of telomers is high. Telomers of general formula C6H5CH2-(CH2CHCl)nCl (n=1–3) were isolated.

Reaction of vinyl chloride with bromoform and related compounds in the presence of coordination initiators based on Fe(CO)5

1. The telomerization of vinyl chloride (VC) with bromoform, with initiation by coordination initiators based on Fe(CO)5, proceeds with a greater conversion of the telogen and an increased yield of lower telomers when compared with initiation by benzoyl peroxide. Together with the CHBr2 (CH2CHCl)nBr (n=1−3) telomers, a small amount of 1,3-dibromo-1,3-dichloropropane is formed. 2. Under the reaction conditions, the CHBr2CH2CHClBr telomer is capable of reacting with VC, with cleavage of the C-Br bonds of both the CHBr2 and CHClBr groups. 3. We were able to add 1,1,3-tribromopropane and 1,3-dibromo-1-chloropropane to VC by initiation with Fe(CO)5 + DMF.

Telomerization of vinylidene fluoride with sulfuryl chloride fluoride

1. The products of the radical telomerization of vinylidene fluoride with FSO2C1, which contain one, two, and three monomeric units in the chain, were isolated. 2. Besides the telomer homologs with the usual structure, the telomer FSO2CH2CF2CF2CH2-CH2CF2Cl, with a reverse addition of the central monomeric unit, is also formed. 3. Because of the substantial difficulties due to the unfavorable polar factors in the chain growth step the distribution of the telomerization products of vinylidene fluoride with FSO2Cl is shifted toward T1 when compared with the telomerization of vinyl chloride with FSO2Cl.

Telomerization of ethylene and vinyl chloride with sulfuryl chloride fluoride

1. We have isolated the products of the radical telomerization of ethylene with FSO2Cl, which contain two monomer units in the chain, and of vinyl chloride with FSO2Cl, which contain one, two, or three monomer units in the chain. 2. Sulfuryl chloride fluoride is a more efficient chain transfer agent than CCl4. Chain transfer to FSO2Cl and the formation of telomers with n=1 by the FSO2CH2ĊH2 and FSO2CH2ĊHCl radicals are inhibited by their high electrophilicity. 3. The Fe(CO)5-DMF system initiates the telomerization of vinyl chloride with FSO2Cl and favors lower telomer homologs.

Reaction of gem-trichloroalkanes with unsaturated compounds in presence of Fe(CO)5 and a cocatalyst

The following reactions were effected in the presence of the coordination initiators Fe(CO)5 + i-C3H7OH (or Hexametapol): a) Telomerization of vinyl chloride with 1,1,1-trichloropropane and 1,1,1,3,3-pentachloropropane. Telomers that contain 1–3 monomeric units in the molecule were isolated, b) The addition of 1,1,1,3-tetrachloropropane and 1,1,1-trichloroethane to isobutylene; the adducts were obtained in good yields, c) The reaction of allyl chloride with 1,1,1,3-tetrachloropropane, which leads to the formation of the adduct and by-products as the result of the partial fragmentation of the ClCH2CH2CCl2CH2CHCH2Cl radicals with the cleavage of chlorine atom.

Telomerization of vinyl chloride with methyl chloroacetate

1. The telomerization of vinyl chloride with methyl chloroacetate, initiated by tertbutyl peroxide, leads mainly to the formation of two series of products: H(CHClCH2)nCHClCO2-CH3 and C1CH2CO2CH2(CH2CHCl)nH. 2. Rearrangement of the radicals with a 1,3-migration of the H atom is practically nonexistent in this process.

Telomerization of vinyl chloride with methyl propionate

The teloHierization of vinyl chloride with methyl propionate was accomplished and it was shown that telomers of type\(\begin{array}{*{20}c} {H(CHClCH_2 )_n CHCOOCH_3 (n = 1,2)} \\ | \\ {CH_3 } \\ \end{array} \) are formed.

Pressure sensitivity of reactions of substitution at C-H, C-Cl, and C-Br bonds in the radical telomerization of ethylene, propylene, and vinyl chloride by polyhalomethanes

1. The competitive kinetics was studied with a calculation of the constants of chain transfer in the radical telomerization of vinyl chloride (60°), ethylene and propylene (95°) with CCl4, CHCl3, and CBrCl3 at pressures up to 2400 kg/cm2. The peculiarities of these ten systems permitted an unambiguous isolation of the elementary step of substitution with the participation of aliphatic radicals and a consideration of the dependence of its volume of activation on the nature of the attacking radical and the type of bond to be broken. 2. Using several methods of calculation it was shown that the volumes of activation of substitution reactions vary in the series C-H C-C1>C-Br for CCl3[CH2CH(CH3)]n; and remain constant for CCl3(CH2CHCl)n at n=1–3. A high sensitivity of chain transfer to pressure for all the indicated bonds forα-chloro-orα-methyl-substituted aliphatic radicals was detected. The volumes of activation of homolytic substitution with cleavage of C-Hal bonds depend less on the nature of the attacking radical than chain transfer at the C-H bond. 3. A change in the polar characteristics of the activated complexes of reactions of homolytic substitution at the C-H and C-Hal bonds does not make any significant contribution to the volumes of activation. The values of the parameters of activation of such reactions are evidently determined by the volume of the atoms and groups around the reaction center and by differences in the length of the bond to be broken (formed) in the transition state.

Catalysis of telomerization of vinyl chloride with CCl4 by some iron compounds and effect of adding CH3OH

1. In the radical telomerization of vinyl chloride with CCl4, catalyzed by Fe(CO)5, Fe(AA)3 or FeCl3, the yield of the adduct increases when compared with peroxide initiation. The amount of the adduct passes through a maximum when the catalyst concentration is increased. An increase in the relative yield of the higher telomer homologs, as well as a reduction in the telomerization rate, is observed in the presence of Fe(CO)5 or FeCl3 when dilution is with methanol. 2. It was shown that direct reaction of the intermediate or starting chlorine-containing iron compound with electrophilic CCl3(CH2CHCl)n. radicals is possible via the mechanism of ligand transfer.

Telomerization of vinyl chloride by polychloroalkanes containing the CCl3 group in the presence of iron pentacarbonyl and alcohol

1. The radical telomerization of vinyl chloride by 1,1,1,3-tetrachloropropane and 1,1,1-trichloroethane was studied in the presence of Fe(CO)5 in isopropyl alcohol medium, leading to the formation of compounds with the structure RCH2CCl2 (CH2CHCl)nCl, where R=H, ClCH2. Telomer homologs with n=1–3 were isolated, and their structure demonstrated. 2. Iron pentacarbonyl, in conjunction with isopropyl alcohol, is not only an initiator of this telomerization, but at definite concentrations it participates in chain propagation, changing the yields of the telomer homologs and the particular transfer constants.