75-33-2Relevant academic research and scientific papers
A process for the preparation of isoflavones propanethiol
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Paragraph 0062-0065, (2017/04/03)
The invention discloses a method for synthesizing isopropyl mercaptan from propylene and hydrogen sulfide. According to the method, a heat insulation type fixed bed reactor is used and isopropyl mercaptan is synthesized of hydrogen sulfide and propylene in the presence of a solid acid catalyst according to a continuous production process. The method disclosed by the invention has the advantages that the reaction conditions are easy to control, the yield is high, the process is simple, and the environmental pollution is reduced.
Quantitative Reactivity Scales for Dynamic Covalent and Systems Chemistry
Zhou, Yuntao,Li, Lijie,Ye, Hebo,Zhang, Ling,You, Lei
supporting information, p. 381 - 389 (2016/01/26)
Dynamic covalent chemistry (DCC) has become a powerful tool for the creation of molecular assemblies and complex systems in chemistry and materials science. Herein we developed for the first time quantitative reactivity scales capable of correlation and prediction of the equilibrium of dynamic covalent reactions (DCRs). The reference reactions are based upon universal DCRs between imines, one of the most utilized structural motifs in DCC, and a series of O-, N-, and S- mononucleophiles. Aromatic imines derived from pyridine-2-carboxyaldehyde exhibit capability for controlling the equilibrium through distinct substituent effects. Electron-donating groups (EDGs) stabilize the imine through quinoidal resonance, while electron-withdrawing groups (EWGs) stabilize the adduct by enhancing intramolecular hydrogen bonding, resulting in curvature in Hammett analysis. Notably, unique nonlinearity induced by both EDGs and EWGs emerged in Hammett plot when cyclic secondary amines were used. This is the first time such a behavior is observed in a thermodynamically controlled system, to the best of our knowledge. Unified quantitative reactivity scales were proposed for DCC and defined by the correlation log K = SN (RN + RE). Nucleophilicity parameters (RN and SN) and electrophilicity parameters (RE) were then developed from DCRs discovered. Furthermore, the predictive power of those parameters was verified by successful correlation of other DCRs, validating our reactivity scales as a general and useful tool for the evaluation and modeling of DCRs. The reactivity parameters proposed here should be complementary to well-established kinetics based parameters and find applications in many aspects, such as DCR discovery, bioconjugation, and catalysis.
Mechanism of the Solution-Phase Reaction of Alkyl Sulfides Atomic Hydrogen. Reduction via a 9-S-3 Radical Intermediate
Tanner, Dennis D.,Koppula, Sudha,Kandanarachchi, Pramod
, p. 4210 - 4215 (2007/10/03)
The low selectivity of benzyl alkyl sulfide fragmentation subsequent to its reaction with atomic hydrogen is indicative of a reaction that proceeds via an early transition state. The competitive reduction of a series of substituted-benzyl alkyl sulfides was insensitive to the substituent on the aromatic ring (ρ = -0.13, r = 0.99). The relative rates of fragmentation of a series of the substituted-benzyl alkyl sulfides gave a V-shaped Hammett plot. Both electron-donating and electron-withdrawing groups destabilized the transition state (ρ = +0.99, r = 0.999; ρ = -0.82, r = 0.992). Since the relative rates of disappearance of the alkyl benzyl sulfides are not substituent dependent, but the relative rates of fragmentation are, a 9-S-3 intermediate is preferred as the structure leading to products.
Phosphosulfonate herbicides
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, (2008/06/13)
This invention pertains to phosphosulfonates, having the general formula STR1 wherein Y is phenyl, naphthyl, benzyl, a (C5 -C8)cycloalkyl, a 5-membered heteroaromatic ring, a 6-membered heteraromatic ring, a fused 5,6-membered heteroaromatic ring, or a fused 6,6-membered heteroaromatic ring; and X is oxygen or sulfur; and R1 and R2 are each independently selected from substituted or unsubstituted alkyl, alkoxy, alkylthio, alkenyloxy, alkynyloxy, haloalkoxy, cyanoalkoxy, alkoxyalkoxy, cycloalkyloxy, cycloalkylalkoxy, alkylideneiminooxy, chloro, amino, phenyl or phenoxy; or R1 and R2 are both alkoxy, taken together with the phosphorus atom to form a 6-membered oxygen-containing ring; compositions containing these compounds and their use as herbicides.
NO-Group transfer (transnitrosation) between S-nitrosothiols and thiols. Part 2
Barnett, D.Jonathan,Rios, Ana,Williams, D. Lyn H.
, p. 1279 - 1282 (2007/10/03)
The kinetics of NO-group transfer have been measured for the reaction between a nitrosothiol (HOCH2CH2SNO) and nine thiols, mostly based on the cysteine structure.The reaction is second-order and there is evidence for a steric effect for thiols containing 1,1-dimethyl substituents (penicillamine derivatives).Reaction occurs via the thiolate anion as shown by the pH-rate constant profile, and a full kinetic analysis for the reactions of two thiols (N-acetylcysteine and glutathione) is quantitatively in agreement with this mechanism.Variation of the nitrosothiol structure for reaction with N-acetylcysteine shows that electron-withdrawing substituents in the nitrosothiol promote reaction; there is a similarity with the corresponding reactions of alkyl nitrites.
Phosphosulfonate herbicides
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, (2008/06/13)
This invention pertains to phosphosulfonates, having the general formula STR1 wherein Y is phenyl, naphthyl, benzyl, a (C5 -C8)cycloalkyl, a 5-membered heteroaromatic ring, a 6-membered heteraromatic ring, a fused 5,6-membered heteroaromatic ring, or a fused 6,6-membered heteroaromatic ring; and X is oxygen or sulfur; and R1 and R2 are each independently selected from substituted or unsubstituted alkyl, alkoxy, alkylthio, alkenyloxy, alkynyloxy, haloalkoxy, cyanoalkoxy, alkoxyalkoxy, cycloalkyloxy, cycloalkylalkoxy, alkylideneiminooxy, chloro, amino, phenyl or phenoxy; or R1 and R2 are both alkoxy, taken together with the phosphorus atom to form a 6-membered oxygen-containing ring; compositions containing these compounds and their use as herbicides.
Preparation of ZnS and CdS by thermal degradation of (methanethiolato)zinc and -cadmium complexes, [M(SMe)2]n (M = Zn, Cd)
Osakada, Kohtaro,Yamamoto, Takakazu
, p. 2328 - 2332 (2008/10/08)
Reactions of aqueous MeSNa with ZnCl2 and with CdCl2 give the methanethiolato complexes [Zn(SMe)2]n (1a) and [Cd(SMe)2]n (2), respectively. Reaction of MeSH with ZnEt2 in hexane also gives [Zn(SMe)2]n (1b). [Zn(SEt)2]n (3) and [Zn(S-i-Pr)2]n (4) are obtained by reaction of EtSLi and i-PrSLi with ZnI2, respectively. Elemental analyses of the complexes give satisfactory results. Peaks in the X-ray diffraction pattern of 1b are considerably broader than those of 1a. Thermolysis of 1a and 1b at 260°C gives β-ZnS accompanied by evolution of MeSMe in almost quantitative yields. Thermolysis of 2 under similar conditions give CdS as a mixture of α- and β-forms. Thermogravimetric analyses of the thiolato compounds also suggest elimination of MeSMe in the vicinity of 230-240°C. TG curves of 1b and 2 at constant temperatures indicate that the thermolysis obeys first-order kinetics in [M(SMe)2]n. Activation parameters of the reactions are 143 and 191 kJ mol-1, respectively. Thermolysis of 1a obeys autocatalytic type kinetics expressed by the kinetic equation ln [x/(1 - x)] = kt + C (x: reacted fraction). Heating the (ethanethiolato)zinc complex 3 gives ZnS similarly to the case of 1a, 1b, and 2, while thermolysis of 4 is much slower than the reactions of these complexes.
Mitomycin derivatives
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, (2008/06/13)
Novel mitomycin derivatives are characterized by a substituent on the C6 -methyl group. The mitomycin derivatives exhibit anti-tumor and antibacterial activity and have low toxicity.
EFFET PROMOTEUR DES PHOSPHITES ALIPHATIQUES DANS L'ADDITION PHOTO AMORCEE D'H2S SUR LE PROPYLENE EN SOLUTION. I - ETUDE ANALYTIQUE
Brehon, Annick,Couture, Axel,Combier, Lablache A.
, p. 839 - 850 (2007/10/02)
Aliphatic phosphites have a promotor effect in the radical addition in solution of H2S to propylene photoinitiated as well by direct H2S irradiation as by added benzophenone irradiation.For this last reaction, the phosphite used being (CH3O)3P, the solvent polarity has no effect on the reaction.When the solvent used is a poor hydrogen donnor in a radical reaction, such as benzene, there is an induction period in the case of the benzophenone photoinitiated reaction performed in the presence of a phosphite.It increases for a given aliphatic phosphite with the phosphite concentration and varies with the aliphatic phosphites structure.Light intensity has nearly no effect on the development of the last reaction.
Phosphite Radicals and Their Reactions. Examples of Redox, Substitution, and Addition Reactions
Schaefer, K.,Asmus, K.-D.
, p. 2156 - 2160 (2007/10/02)
Phosphite radicals HPO3(-) and PO3(2-), which exist in an acid-base equilibrium with pK = 5.75, are shown to take part in various types of reactions.In the absence of scavengers, they disappear mainly by second-order disproportionation and combination; a first-order contribution to the decay is also indicated.HPO3(-) and PO3(2-) are good reductants toward electron acceptors such as tetranitromethane.In this reactions phosphate and C(NO2)3(-) are formed.Phosphite radicals can, however, also act as good oxidants, e.g., toward thiols and thiolate ions.These reactions lead to the formation of RS. radicals which were identified either directly, as in the case of penicillamine, through the optical absorption of PenS. or more indirectly through equilibration of RS. with RS(-) to the optically absorbing RSSR.(-) disulfide radical anion.A homolytic substitution reaction (SH2) occurs in the reaction of the phosphite radicals with aliphatic disulfides, yielding RS. radicals and phosphate thioester RSPO3(2-).Lipoic acid, as an example of a cyclic disulfide, is reduced to the corresponding RSSR.(-) radical anion and also undergoes the SH2 reaction with about equal probability.An addition reaction is observed between phosphite radicals and molecular oxygen.The resulting peroxo phosphate radicals establish an acid-base equilibrium HPO5(-). PO5(2-). + H(+) with a pK = 3.4.Absolute rate constants were determined for all reactions discussed.
