Vanadium catalysts Vinyl chloride

Titanium—Vanadium Mixed Metal Alkoxides. Titanium—vanadium mixed metal alkoxides, VO(OTi(OR)2)2, are prepared by reaction of titanates, eg, TYZOR TBT, with vanadium acetate ia a high boiling hydrocarbon solvent. The by-product butyl acetate is distilled off to yield a product useful as a catalyst for polymeri2iag olefins, dienes, styrenics, vinyl chloride, acrylate esters, and epoxides (159,160). 

Vanadium oxide as catalyst, 174 Vinyl chloride, manufacture of, using catalysts, 238... 

Friedel-Crafts reaction catalysts like anhydrous aluminum chloride are readily soluble in the nitroalkanes. Solutions containing up to 50% aluminum chloride are easily prepared in nitroalkane solvents. These catalytically active complexes, AICI3-RNO2, can be isolated and used in solvents other than the nitroalkane. The reactants in the Friedel-Crafts reaction are often soluble in the nitroalkane reaction medium. Other catalysts like boron trifluoride (BF3), titanium tetrachloride (TiC ), and stannic tetrachloride (SnClj) are also soluble in the nitroalkane solvents. Reaction types which use nitroparaffins as solvents include alkylation of aromatics, acetylation of aromatics, halogenations, nitrations, and the reaction of olefins and hydrogen sulfide to yield mercaptans. Nitroparaffins are used with catalysts such as alkyl-metal (e.g., triethylaluminum, vanadium, or titanium) salts in the polymerization reactions of alkylene oxides, epichlorohydrin, propylene, butylene, vinyl chloride, and vinyl ethers. The nitroparaffin acts as an activator for the catalyst or can serve as the reaction solvent. 

Polymer Stereochemistry and Optical Activity.—Although stereoregular products from carbocation propagations are not common, there are some notable examples, perhaps the most important being the isotactic materials from alkyl vinyl ethers. Recently, novel catalysts based on phosphoryl and thionyl chlorides with vanadium pentoxide have been added to those initiator systems capable of producing stereospecific reactions. 

Improvements in available methodology for the oxidation of alkenes to oxirans have been described. Glycidol can be obtained in 90% yield by heating allyl alcohol with cumene hydroperoxide at 110 °C using vanadium oxychloride as catalyst. Oxidation of isoprene with peroxyformic acid gave an 80% crude yield of the vinyl oxiran, which was treated with lithium chloride and cupric chloride to give the useful synthon (15), a key intermediate in the synthesis of vitamin A from j3-ionone. This modified synthesis employs a hitherto unprecedented oxidative chlorination of a vinyl oxiran (Scheme 4). Previously, the best known method for the oxidation... 

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