The reactions or trispentafluorophenylstibine with halogens and interhalogens

Conductometric titration studies show that the reactions of trispentafluorophenylstibine with halogens and interhalogens lead to non-conducting species. Molar conductance values of the adducts (C₆F₅)₃SbCl₂ and (C₆F₅)₃SbBr₂ in acetonitrile are very low. The reaction of trispentafluorophenylstibine with iodine chloride and iodine bromide gives (C₆F₅)₃SbCl₂ and (C₆F₅)₃SbBr₂ respectively and not the expected interhalogen adducts.     

Preparation of highly fluorinated cyclopropanes and ring-opening reactions with halogens

Various highly fluorinated cyclopropanes 1 were prepared by reaction of the appropriate fluorinated olefins with hexafluoropropylene oxide (HFPO) at 180 degrees C. The fluorinated nitrile 1e was converted to the triazine derivatives 2a and 2b by catalysis with Ag(2)O and NH(3)/(CF(3)CO)(2)O, respectively. The fluorinated cyclopropanes reacted with halogens at elevated temperatures to provide the first useful, general synthesis of 1,3-dihalopolyfluoropropanes. At 150-240 degrees C, hexafluorocyclopropane and halogens X(2) produce XCF(2)CF(2)CF(2)X (X = Cl, Br, I) in 50-80% isolated yields. Pentafluorocyclopropanes c-C(3)F(5)Y [Y = Cl, OCF(3), OC(3)F(7) and OCF(2)CF(CF(3))OCF(2)CF(2)Z; Z = SO(2)F, CN, CO(2)Me] react regiospecifically at 150 degrees C to give XCF(2)CF(2)CFXY, c-C(3)F(5)Br reacts regioselectively with Br(2) to give a 16.7:1 mixture of BrCF(2)CF(2)CFBr(2):BrCF(2)CFBrCF(2)Br, whereas c-C(3)F(5)H reacts unselectively with I(2) to produce a statistical 2:1 mixture of ICF(2)CF(2)CFHI:ICF(2)CFHCF(2)I. Tri- and di(pentafluorocyclopropyl) derivatives 2 also undergo ring-opening reaction with halogens to give 16 and 17. Upon treatment of tetrafluorocyclopropanes 1j, 1k, and 1l with Br(2) or I(2), ring opening occurred exclusively at substituted carbons to give XCF(2)CF(2)CXY(2). Thermolysis of the ring-opened product ICF(2)CF(2)CFIOR(F) at 240 degrees C gave R(F)I and ICF(2)CF(2)COF in high yields.     

Stability of polynitropentanes

Conclusions The -nitro group in 1,3,5-polynitropentanes affects the reaction site located at the terminal carbon atom by a field effect mechanism as a consequence of steric approximation. As a result, the dissociation energy of the C-NO₂ bond is reduced by 20–30 kJ/mole.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2822–2824, December, 1984.The authors thank L. T. Eremenko and G. V. Oreshko for providing samples of the compounds studied.     

Ring-opening reactions of difluoro(methylene)cyclopropanes with halogens and amines

The distal and proximal bond of difluoro(methylene)cyclopropanes (F2MCPs) could be cleaved, respectively, under different conditions to give the corresponding ring-opening products. The reaction mechanisms are discussed.     

Effect of halogens on the activity of halonitrobenzenes in reactions with carbanions

On the basis of competition experiments using a model VNS reaction of chloromethyl phenyl sulfone with halonitrobenzenes it was shown that halogen substituents activate electron-deficient nitroarenes for the addition of carbanions whereas they protect the positions they occupy against the addition.     

Competitive binding of fluorosulfate anion in reactions of halogens and nitronium borofluoride with olefins

Conclusions Reactions of olefins with chlorine in the presence of fluorosulfonic acid salts lead to-chloroalkyl fluorosulfates together with 1,2-dichlorides. The addition of nitronium borofluoride to ethylene in the presence of tetraethylammonium fluorosulfate gives 2-nitroethyl fluorosulfate. These reactions confirm the general character of the competitive binding of superweak nucleophiles in Ad_E reactions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 389–391, February, 1985.     

Reaction of halogens with trialkylaluminums

Summary A study was made of the reaction of trialkylaluminums with halogens, which results in the formation of alkyl halides.     

Ynaziridines and their reactions with amines

On the basis of the results of IR and UV spectroscopy, a considerable decrease in the efficacy of the conjugation of the unshared pair of the nitrogen atom with a carbonyl group in ynaziridines as compared with ynamines has been shown. The difference in the electronic structures of these compounds finds its reflection in their chemical behavior: the electrophilicity of the triple bond in an ynaziridine is higher than that in the analogous ynamine in reactions with amines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 618–622, May, 1985.     

Electron-transfer reactions of the halogens and their compounds : Limiting conditions for the quantitative reaction of bromate with arsenic(iii) and antimony(iii)

The limits of hydrochloric acid concentration within which the titrimetric determination of antimony(III) and arsenic(III) with bromate is quantitative within the normal precision of careful volume measurement (0.04%), are defined for both visual indication with rosaniline hydrochloride and potentiometric indication, in media initially containing no or 0.l M bromide. These reactions are independent of the nature of the reductant, the rate-controlling step being the fourth-order reaction producing the active oxidising species. Rate constants and energy of activation were determined. The kinetic and potentiometric investigations were used to elucidate the origins of the errors arising under conditions outside the ranges of quantitative reaction.     

Reactions of 4H-selenopyrans with halogens

The reactions of 2,4,4,6-tetraphenyl-4H-selenopyran with chlorine or bromine give the corresponding 1,1-dichloro- or 1,1-dibromo-4H-selenopyrans, whereas the reaction of 2,4,6-triphenyl-4H-selenopyran with bromine gives 2,4,6-triphenylselenopyrylium tribromide.     

Interaction of N-vinylbenztriazole with halogens and hydrogen halides

Russian Chemical Bulletin -     

Reactions of cyanotrihydroborate ion and its derivatives with halogens

The addition of an equivalent of Cl₂, Br₂ or I₂ to a solution of Na[H₃BCN] in glyme (1,2-dimethoxyethane) yields the cyanoborane cyclic oiligomers previously reported. The addition of an excess of a Lewis base (e.g. a pyridine, a tertiary amine or a tertiary phosphine) to the cyanoborane yields a cyanoborane adduct, LBH₂CN. The addition of an excess of chlorine yields a solution believed to contain [glyme]-BH₂CN. This solution reacts slowly with Lewis bases (L) to yield LBH₂CN, and small amounts of chlorinated cyanoborane adducts. The proportion of chlorinated products relative to LBH₂CN increases as the amount of moisture in the reaction mixture increases and as the base strength of L is reduced. The chlorination of LBH₂CN in moist benzene yields LBCl₂CN as the principal product when L is pyridine, while a complex misture is obtained when L = (C₂H₅)₃N.     

α-Acetylenic ethyleneimides and their reactions with amines

The reaction of aziridines with phenyl and p-chlorophenylpropiolyl chlorides at —30 to 60°C leads only to 1,2-addition products, viz., -acetylenic ethyleneimides, or their isoraerization products, viz., 2-ethynyl-substituted 2-oxazolines. Reactions with amines showed that the p-chlorophenylpropiolic acid ethyleneimides obtained are mild N-acylating agents.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1064–1067, August, 1980.