556-64-9Relevant articles and documents
Nonequilibrium solvent polarization in kinetics of SN2 reactions
Jaworski
, p. 61 - 66 (2003)
The solvent effect on the experimental activation barriers for the reactions of methyl iodide with chloride and thiocyanate ions was analyzed according to the Marcus and Shaik theories, considering SN2 mechanism in terms of a single electron shift. The linear increase in the solvent reorganization energy of the Marcus theory (after removing contributions from the specific solvation) with the solvent Pekar factor, describing the effect of the nonequilibrium solvent polarization, was observed for six aprotic solvents. The direct support of the title effect based on the Shaik theory was less evident; however, in general, the calculated activation barriers in 10 solvents change parallel with the experimental ones.
Halomethane biosynthesis: Structure of a SAM-dependent halide methyltransferase from arabidopsis thaliana
Schmidberger, Jason W.,James, Agata B.,Edwards, Robert,Naismith, James H.,O'Hagan, David
, p. 3646 - 3648 (2010)
It's a gas ! The structure of the halomethane-producing halo/thiocyanate methyltransferase enzyme from plants has been determined. The halide ion and the methyl group of S-adenosyl-L-methionine (SAM) were modeled into the active site (see picture; chloride: green sphere; SAM: C green, O red, S yellow, N blue), which indicated their predisposition for reaction. (Figure Presented)
Vapor generation of inorganic anionic species after aqueous phase alkylation with trialkyloxonium tetrafluoroborates
D'Ulivo, Alessandro,Pagliano, Enea,Onor, Massimo,Pitzalis, Emanuela,Zamboni, Roberto
experimental part, p. 6399 - 6406 (2010/04/06)
Aqueous phase reaction of trialkyloxonium tetrafluoroborates, R 3O+BF4- (R=Me, Et) has been tested in the alkylation of simple inorganic anionic substrates such as halogen ions, cyanide, thiocyanate, sulphide an
Polymer-supported thiocyanate as new, versatile and efficient polymeric reagent for conversion of alkyl halides to corresponding alkyl thiocyanates under mild conditions
Zarchi, Mohammad Ali Karimi
, p. 1299 - 1302 (2008/02/13)
Crosslinked poly(N-methyl-4-vinylpyridinium)thiocyanate [P 4-Me]SCN (II) is prepared easily and is used as a new polymeric reagent for synthesis of alkyl thiocyanates from alkyl halides under mild and nonaqueous conditions. The used polymeric reagent usually can be removing quantitatively and be regenerated.
Using Kamlet-Taft solvent descriptors to explain the reactivity of anionic nucleophiles in ionic liquids
Crowhurst, Lorna,Falcone, Ruben,Lancaster, N. Llewellyn,Llopis-Mestre, Veronica,Welton, Tom
, p. 8847 - 8853 (2007/10/03)
In this paper, we report the effect of ionic liquids on substitution reactions using a variety of anionic nucleophiles. We have combined new studies of the reactivity of polyatomic anions, acetate, trifuoroacetate, cyanide, and thiocyanide, with our previous studies of the halides in [C4C 1Py][Tf2N], [C4C1py][TfO], and [C4C1im][Tf2N] (where [C4C 1im]+ is 1-butyl-3-methylimidazolium and [C 4C1py]+ is 1-butyl-1-methylpyrrolidinium) and compared their reactivities, k2, to the same reactions in the molecular solvents dichloromethane, dimethylsulfoxide, and methanol. The Kamlet-Taft solvent descriptors (α, β, π*) have been used to analyze the rates of the reactions, which were found to have a strong inverse dependency on the α value of the solvent. This result is attributed to the ability of the solvent to hydrogen bond to the nucleophile, so reducing its reactivity. The Eyring activation parameters (ΔH? and ΔS?), while confirming the reaction mechanism, do not offer obvious correlations with the Kamlet-Taft solvent descriptors.
Flash vacuum pyrolysis (F.V.P.) of 1,2,4-benzotriazine derivatives
Riedl, Zsuzsanna,Hajós, Gy?rgy,Peláez, Walter J.,Gafarova, Ioulia T.,Moyano, Elizabeth L.,Yranzo, Gloria I.
, p. 851 - 856 (2007/10/03)
Flash vacuum pyrolysis of 3-methylsulfanyl-1,2,4-benzotriazine N-oxide, 3-methylsulfanyl-1,2,4-benzotriazine, and 3-phenyl-1,2,4-benzotriazine are described. The N-oxide derivative underwent deoxygenation between 500 and 600°C, whereas at higher temperatures both methylsulfanyl compounds, besides yielding the same products, also gave benzimidazole formed by an independent mechanism. Transformation of these derivatives between 600 and 750°C led to formation of a complex reaction mixture indicating the radical nature of the processes. The phenyl substituted derivative was studied between 575 and 650°C and afforded benzonitrile and traces of biphenylene.
Nucleophilicity towards a Saturated Carbon Atom: Rate Constants for the Aminolysis of Methyl 4-Nitrobenzenesulfonate in Aqueous Solution. A Comparison of the n and N+ Parameters for Amine Nucleophilicity
Bunting, John W.,Mason, Jacqueline M.,Heo, Christina K. M.
, p. 2291 - 2300 (2007/10/02)
Second-order rate constants (kNu) have been measured in aqueous solution (I = 0.1 mol dm-3, 25 deg C) for the SN2 reactions of methyl 4-nitrobenzenesulfonate with ammonia, 41 primary amines, 20 secondary amines,29 tertiary amines and 7-anionic nucleophiles.For the aminolysis reactions, Broensted-type correlations of nucleophilicity with basicity require the classification of all amines in terms of strictly defined structural classes with βnuc in the range 0.15-0.39.Swain-Scott plots indicate that simple amines, water and other light-atom nucleophiles (hydroxide, azide and cyanide anions) are five times more reactive than heavy-atom nucleophiles (thiosulfate, thocyanate, iodide and bromide ions).For amine nucleophiles there is a close linear correlation (of slope 0.44 , and including both primary and secondary amines) between log kNu for the aminolysis of methyl 4-nitrobenzenesulfonate and log kNu for amine addition to the 1-methyl-4-vinylpyridinium cation.This correlation demonstrates a close linear relationship between the Swain-Scott n parameter and Ritchie's N+ parameter for amine nucleophiles in aqueous solution (N+ = 2.1n - 4.3).
Biomimetic catalysis of SN2 reactions through cation-π interactions. The role of polarizability in catalysis
McCurdy, Alison,Jimenez, Leslie,Stauffer, David A.,Dougherty, Dennis A.
, p. 10314 - 10321 (2007/10/02)
Cyclophane hosts 1 and 2 have been shown to be effective catalysts for both the alkylation of quinoline structures to produce quinolinium salts and the dealkylation of sulfonium salts to produce sulfides. Thus, reactions that develop positive charge in the transition state and reactions that destroy positive charge are accelerated. The former observation is not surprising, given the well-documented ability of these hosts to bind cations through the cation-π interaction. The catalysis of the dealkylation reactions, however, along with several other observations, suggests that some other factor is involved in the catalysis. It is proposed that the high polarizability of the transition states is well matched to the very polarizable hosts and that this contributes to the catalysis.
N-Phenylpyrazole derivatives
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, (2008/06/13)
The invention provides N-phenylpyrazole derivatives of the formula: wherein R1 represents alkyl optionally substituted by halogen, R2 represents alkyl, alkenyl or alkynyl optionally substituted by halogen, R3 represents a phenyl group substituted in the 2--position by halogen; in the 4-position by optionally halo substituted alkyl or alkoxy; and optionally in the 6-position by halogen; and m and n are independently 0, 1 or 2; which are active against arthropod, plant nematode, helminth and protozoal pests.
