42345-81-3Relevant academic research and scientific papers
Intramolecular Geminal and Vicinal Element Effects in Substitution of Simple Bromo(chloro)alkenes by Methoxide and Thiolate Ions. An Example of a Single Step Substitution?
Beit-Yannai, Michal,Rappoport, Zvi,Shainyan, Bagrat A.,Danilevich, Yuri S.
, p. 8049 - 8057 (1997)
Intramolecular element effects kBr/kCl for substitution of geminal bromochloroalkenes BrC(Cl)=C-(Br)Cl (1), BrC(Cl)=CCl2 (2), Me2C=C(Br)Cl (3), and XCH=C(Br)Cl (X = Cl, 4; X = Br, 5), with MeO- and RS- nucleophiles were investigated. 3 did not give substitution, and 4 and 5 gave substitution with MeO- via an initial elimination (to acetylene)-addition route, followed by further reactions. In reactions of 4 with thiolates, geminal element effects of 2-10 were obtained. Formation of RSC(Cl)=C(Cl)Y, Y = SR, Br, is ascribed to an initial halophilic reaction, followed by addition of RSCl to the formed acetylene. Reaction of 2 with MeO- gave a high vicinal element effect, and RS- gave a high geminal element effect. Reaction of 1 with both MeO- and RS- ions gave high (2 orders of magnitude) geminal element effects, which were interpreted as indicating a rate-determining C-X bond cleavage. This is supported by the high kBr/kCl intermolecular element effects (k(1)/k(Cl2C=CCl2) with MeO- and PhCH2S- ions. Mechanistic alternatives based on these observations are discussed.
NUCLEOPHILIC REACTIONS AT A VINYLIC CENTER. XXVIII. FLUOROCHLOROETHENES AND FLUOROBROMOETHENES IN REACTIONS WITH SODIUM ALCOHOLATES AND ARENETHIOLATES
Shainyan, B. A.,Vereshchagin, A. L.
, p. 1981 - 1988 (2007/10/02)
During the reaction of halogenoethenes (Z+E)-CHX=CFX with sodium methoxide and with sodium p-thiocresolate in methanol initial attack by the nucleophilic takes place at the carbon atom attached to the fluorine atom.In the reactions with sodium methoxide the intermediate monosubstitution products are more reactive than the initial halogenoethenes, and the main reaction products are the ortho esters CHXYC(OMe)3.An "element effect", i.e., concurrent substitution of F and Cl(Br) in the reaction with sodium methoxide, was discovered.With sodium p-thiocresolate trifluorochloroethene gives the product from substitution of the chlorine atom and a small amount of the addition product as impurity.The other ethenes give substitution, addition, and halogenophilic reduction products and also the products from further transformations (hydrolysis and decarboxylation).
