1.3- dichloropropene, addition

The process involving aHyl alcohol has not been iadustriaHy adopted because of the high production cost of this alcohol However, if the aHyl alcohol production cost can be markedly reduced, and also if the evaluated cost of hydrogen chloride, which is obtained as a by-product from the substitutive chlorination reaction, is cheap, then this process would have commercial potential. The high temperature propylene—chlorination process was started by SheH Chemical Corporation ia 1945 as an iadustrial process (1). The reaction conditions are a temperature of 500°C, residence time 2—3 s, pressure 1.5 MPa (218 psi), and an excess of propylene to chlorine. The yield of aHyl chloride is 75—80% and the main by-product is dichloropropane, which is obtained as a result of addition of chlorine. Other by-products iaclude monochioropropenes, dichloropropenes, 1,5-hexadiene. At low temperatures, the amount of... 

The dkect high temperature chlorination of propylene continues to be the primary route for the commercial production of aHyl chloride. The reaction results in aHyl chloride selectivities of 75—80% from propylene and about 75% from chlorine. Additionally, a significant by-product of this reaction, 1,3-dichloropropene, finds commercial use as an effective nematocide when used in soil fumigation. Overall efficiency of propylene and chlorine use thus is significantly increased. Remaining by-products include 1,2-dichloropropane, 2-chloropropene, and 2-chloropropane. 

As shown, ia the case of chlotination of aEyl chloride, the resonance states of the chloroaEyl radical iatermediates are not symmetrical and their propagation reactions lead to the two different dichloropropene isomers ia an approximate 10 90 ratio (26). In addition, similar reactions result ia further substitution and addition with products such as trichloropropanes, trichloropropenes, tetrachloropropanes, etc ia diminisbing amounts. Propylene dimerization products such as 1,5-hexadiene, benzene, 1-chloropropane, 2-chloropropane, high boiling tars, and coke are also produced ia smaE amounts. 

The addition of elemental fluorine to the hydrochloroalkenes (Z)- and ( )-l,2-dichloroethene (7), 1,1,2-trichloroethene, 1,3-dichloropropene, and 2,3-dichloropropene has been studied.72 Hydrochlorofluoroalkanes are obtained, for example, the reaction of 7.72... 

Bandini, M., Cozzi, P. G., Melchiorre, P., Morganti, S., Umani-Ronchi, A. Cr(Salen)-Catalyzed Addition of 1,3-Dichloropropene to Aromatic Aldehydes. A Simple Access to Optically Active Vinyl Epoxides. Org. Lett. 2001, 3,1153-1155. 

Alternatively, 2-(chloromethyl)-3-iodo-l-propene reacted with aldehydes or ketones to give after basic treatment methylenetetrahydrofuran in excellent yields. The reaction is as expected chemo- and regioselective conjugated carbonyl compounds gave 1,2-addition, and aldehydes react more preferably than ketones [106]. Simharly, 3-chloro-homoallylic alcohols were prepared in high yields from the reaction of 2,3-dichloropropene with carbonyl compounds in a two-phase system containing a small amount of acetic acid. In this reaction, the presence of water in the reaction medium was shown to be essential as the reaction did not occur under non-aqueous conditions [107]. 

Smith was granted a patent (30) covering a continnons process for producing cls-trans 1,2,3-trichloropropene through chlorination of mixtures of 2-chloropropene and 2,3-dichloropropene In vapor phase under chlorine substitution conditions. The addition of chlorine to cis-trans 1,2,3-trichloropropene furnished 1,1,2,2,3-pentachloropro-pane in 74% yield. The dehydrochlorlnatlon of this Intermediate with a base afforded 1,1,2,3-tetrachloro-l-propene (31). 

Umani-Ronchi adapted the Furstner protocol to achieve the first catalytic, enantioselective variant of this reaction. The chiral chromium salen complex was prepared from the in situ reduction of the anhydrous CrCb to CrCl2 with an excess of manganese metal, followed by complexation with the salen ligand 8 in the presence of catalytic triethylamine." Then the addition of allylic chloride (9) to aldehydes 10 to give the allylic alcohols 11 in moderate yields and in up to 95% ee. The same groups employed the same conditions for the addition of 2-butenyl bromides to aldehydes to achieve up to 83 17 syn/anti of allylic alcohol products and for the addition of 1,3-dichloropropene to aromatic aldehydes to obtain the syn chlorohydrin adduct in modest yield which were further converted to optically active vinyl epoxides. The [Cr(salen)]-catalyzed addition of propargyl halides to aromatic aldehydes allowed the synthesis of enantiomerically enriched homopropargyl alcohols in moderate yields with up to 56% ee. ... 

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