Carbon tetrachloride to olefins

Addition, acetic acid to bicyclo[2.2.1]-hepta-2,5-diene to give nortri-cyclyl acetate, 46, 74 1,2,3-benzothiadiazole 1,1-dioxide to cyclopentadiene, 47, 8 benzyne to tetraphenylcyclopentadie-none, 46,107 Br, F to 1-heptene, 46,10 carbon tetrachloride to olefins, 46, 106... 

Similarly, several other covalent molecules, such as halogens, organometallic compounds, and carbon tetrachloride, take part in such reactions. Susuki and Tsuji reported that addition of carbon tetrachloride to olefins and carbonyla-tion are catalyzed by dinuclear metal carbonyl complexes like [7r-CsHsFe(CO)2]2 and [7r-CsH5Mo(CO)3 ]2 S8-S9>. 

The compounds [Mocp(CO)3] and [Fecp(CO)2]2 catalyze the reaction of addition of carbon tetrachloride to olefins " ... 

The addition of carbon tetrachloride to olefin double bonds catalyzed by peroxides as radical initiator or by transition metal complexes is known as Kharasch reaction [59]. The reaction proceeds in a... 

A similar method can be used for the addition of carbon tetrachloride to nonpolymerizable olefins (e.g., 1-octene, 2-octene, 1-butene, 2-butene) pure adducts are obtained in yields of over 90% if the components are allowed to react at 100° for 6 hours. Adducts of carbon tetrachloride with vinylic monomers (styrene, butadiene, acrylonitrile, methyl acrylate, etc.) can be prepared in good yields by substituting cupric chloride dihydrate in acetonitrile for ferric chloride hexahydrate and benzoin. 

Table 8.8 ATRA of carbon tetrachloride to various olefins catalyzed by ruthenium indenylidene complexes.

Reaction with olefins. Chromyl chloride reacts with an olefln, for exampli cyclohexene, in carbon tetrachloride to give a brown solid of the approximati... 

Free Radical Initiated Additions of Carbon Tetrachloride to a-Olefins. 

A more quantitative discussion can be made concerning the fixation of the CCla group which probably also follows mechanism 2a. Kooyman and Farenhorst41 have studied this reaction in two different ways. In one, the addition of carbon tetrachloride to hexadecene-1 was initiated by the action of benzoyl peroxide. The CCla radicals are fixed on the olefin by the reaction ... 

When this experiment is carried out at 80° under otherwise identical conditions no carbon monoxide or butylbenzene is formed the acyl radical is stable at this temperature and reacts with carbon tetrachloride to give the acid chloride or with an olefin to give a ketone. 

Sometimes at low temperatures, it is possible to isolate alkene complexes. At 195 K, VCI4 forms complexes of the type [VCl3(alkene) ] ( = 1,2, alkene = 1-heptene, 1-decene = 2, alkene = acrylonitrile, 1-heptene, 4-methyl-1-pentene) in pentane solution. The formation of colored complexes is also observed in solution of VOCI3 in carbon tetrachloride containing olefins. These complexes decompose immediately after evaporation of the solvent. Stable vanadium(O) complexes containing 6 -cw-pro-penylphenyldiphenylphosphine and orM -allylphenyldiphenylphosphine are known. These complexes are formed from stoichiometric amounts of hexacarbonylvanadium(O). 

Hydrogen fluoride also effects replacement reactions in organic compounds. For example, carbon tetrachloride yields a mixture of chlorofluoromethanes CCI3F, CCI2F2 and so on. Like all the other hydrogen halides, hydrogen fluoride adds on to olefins, for example ... 

Use of the trapping agent is recommended as the most efficient method for running acyloin condensations for many reasons. Among them are (a) the work-up is very simple filter and distil (b) the bis-(silyloxy)olefin is usually easier to store than the free acyloin and is readily purified by redistillation (c) unwanted base-catalyzed side reactions during reduction are completely avoided and (d) the bis-(silyloxy)olefin can be easily converted directly into the diketone by treatment with 1 mole of bromine in carbon tetrachloride.Other reactions are described in Riihlmann s review and in Organic Reactions ... 

Stirring. The succinimide is removed by suction filtration and washed twice with 10-mI portions of carbon tetrachloride. The combined filtrate and washings are fractionally distilled at atmospheric pressure to remove the carbon tetrachloride and excess olefin (steam bath). The residue is distilled under vacuum, giving about 60 % yield of 3-bromo-cyclohexene, bp 68715 mm or 4472 mm. 

The infrared spectrum (neat) shows major absorptions at 2970, 2920, 2855, 1660, 1450, 1375, 1380, 1255, 835, and 660 cm.-1 The proton magnetic resonance spectrum (carbon tetrachloride solution, tetra-methylsilane reference) has a four-line multiplet in the 1.55-1.85 p.p.m. region characteristic of the olefinic methyl protons, two peaks in the 2.0-2.2 p.p.m. region due to the four allylic methylene protons, a doublet at 4.02 p.p.m. (,J = 7.0 Hz.) due to the allylic methylene protons adjacent to the chlorine, a very broad triplet at 5.09 p.p.m.,... 

The infrared spectrum of y-crotonolactone shows two bands in the carbonyl r on at 5.60 and 5.71 fi in carbon tetrachloride (5%) [shifted to 5.61 and 5.71 fi in chloroform (5%)] and carbon-carbon stretching absorption at 6.23 fjt. The nuclear magnetic resonance spectrum shows olefinic peaks centered at 2.15r (pair of triplets) and 3.85r (pair of triplets), each due to one proton, and a two-proton triplet centered at 5.03t (in CCU). 

Unlike boron fluoride, titanium tetrachloride does not catalyze the liquid phase polymerization of isobutylene under anhydrous conditions (Plesch et al., 83). The addition of titanium tetrachloride to a solution of the olefin in hexane at —80° failed to cause any reaction. Instantaneous polymerization occurred when moist air was added. Oxygen, nitrogen, carbon dioxide, and hydrogen chloride had no promoting effect. Ammonia and sulfur dioxide combined with the catalyst if these were added in small quantity only, subsequent addition of moist air permitted the polymerization to occur. Ethyl alcohol and ethyl ether, on the other hand, prevented the polymerization even on subsequent addition of moist air. They may be regarded as true poisons. 

The nature of the chlorinated reagent is crucial for promoting the Kharasch addition reaction (Equation 8.11). The results showed that carbon tetrachloride could be added to various olefins in a regioselective way. Under these reaction conditions, no polymerization products were detected. In contrast, when chloroform was used as the halide source the methyl methacrylate and styrene conversions reached only 33% and 40% with the best performing system (VIII), and a significant fraction of polymers was observed [61]. 

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