Kinetics of the thermal gas-phase isomerization of 1,2-epoxycyclohexane

The kinetics of the gas-phase decomposition of 1,2-epoxycyclohexane has been studied over the temperature range 680–740 K at pressures between 1.6 and 6 torr. Isomerization to cyclohexanone and 2-cyclohexen-1-ol accounts for ca. 97% of the primary reaction products and occurs by first-order, homogeneous, nonradical processes:      

The unimolecular decomposition and isomerization of chemically activated 1-methyl-2,2,3,3-tetrafluorocyclopropane

The reaction of CH₂(¹A₁) with 1,1,2,2-tetrafluorocyclopropane was studied at 300 K and at pressures between 9.0 and 365.0 torr. Chemically activated 1-methyl-2,2,3,3-tetrafluorocyclopropane was formed and two competitive reaction paths, namely decomposition and isomerization, were observed. By fitting the experimental results to calculated values from RRKM theory, we estimated the Arrhenius parameters for both reaction processess as well as the heat of formation of 1-methyl-2,2,3,3-tetrafluorocyclopropane. © John Wiley & Sons, Inc.     

2,2-Bis(trifluoromethyl)-3-cyanoaziridine

Conclusions 1-Tosyloxy-2,2-bis(trifluoromethyl)aziridine with NaCN in DMSO gives 2,2-bis(trifluoromethyl)-3-cyanoaziridine, which is apparently formed via the intermediate 2,2-bis(trifluoromethyl)-1-azirine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1187–1189, May, 1976     

The kinetics and the mechanism of the thermal decomposition of bis(trifluoromethyl) trioxide. The influence of carbonmonoxide on its decomposition

The kinetics of the thermal decomposition of CF₃O₃CF₃ has been investigated in the pressure range of 15–599 torr at temperatures between 59.8 and 90.3°C and also in the presence of CO between 42 and 7°C. The reaction is homogeneous. In the absence of CO the only reaction products are CF₃O₂CF₃ and O₂. The rate of reaction is strictly proportional to the trioxide pressure, and is not affected by the total pressure, the presence of inert gases, and oxygen. The following mechanism explains the experimental results: In the presence of CO there appear CO₂, (CF₃OCO)₂, and CF₃O₂C(O)OCF₃ as products. With increasing temperature the amount of peroxicarbonate decreases, while the amounts of oxalate and CO₂ increase. The rate of decomposition of the trioxide above a limiting pressure of about 10 torr CO is strictly first order and independent of CO pressure, total pressure, and the pressure of the products. The addition of larger amounts of O₂ to the CO containing system chaqnges the course of the reaction.     

Differentiation and electron ionization-induced isomerization of 4,5-Bis(alkylthio)-1,3-dithiole-2-thiones and 1,2-dithiole-3-thiones

The electron impact ionization mass spectra of 4,5-bis(alkylthio)-1,3-dithiole-2-thiones and their 1,2-dithiole-3-thione isomers were studied by accurate mass measurements and linked scans. The relative abundance of ions formed following the extrusion of S₂, CS or CS₂ allows an unambiguous isomer differentiation. Isomerization of molecular ions was studied by means of metastable ion analysis and collision-induced dissociation. The order of reactivity was analogous to that observed in isomerization under photochemical conditions.     

The thermal isomerization of cyclobutenes. XVI. 1,2-bis(trimethylsiloxy)cyclobutene

The gas phase thermal isomerization of 1,2-bis(trimethylsiloxy)cyclobutene has been studied in the temperature range 172°–204°C. The reaction is homogeneous, kinetically first order, and yields 2,3-bis(trimethylsiloxy)buta-1,3-diene as the only product. The rate constants fit the Arrhenius equation These results, taken with those obtained previously, demonstrate the insensitivity of the kinetics of the reaction to the nature of the groups substituted on the 1- and/or 2-positions of the cyclobutene ring.     

1,2-二(2-甲氧基苯基)-1,2-乙二胺的制备方法研究

手性1,2-二(2-甲氧基苯基)-1,2-乙二胺可作为有机小分子催化剂、金属配体前体广泛应用于多种有机合成反应之中,其可以消旋体为原料通过拆分得到。以廉价易得的邻甲氧基苯甲醛为原料,重点针对亚胺中间体还原过程中反应条件苛刻、后处理复杂等问题,首次利用Mg作为还原剂,在室温下,以93%的分离收率得到关键中间体3。通过该关键步骤的放大实验（92%）,进一步评价了该方法的应用潜力。      

Synthesis of (S,S)-1,2-Bis(3,5-DI-Tert-Butylphenyl)Ethane-1,2-Diol

The synthesis of (S,S)-1,2-bis(3,5-di-tert-butylphenyl)ethane-1,2-diol (98.6% ee), which should be useful as a chiral ligand of catalysts in asymmetric inductions, is described.     

The Synthesis of 1,2-Bis(phenylsulfonyl)cycloalkenes

Reaction of the 2-(phenylthio)cycloalkanones 11–13 with thiophenol and chlorotrimethylsilane afforded the 1,2-bis(phenylthio)cycloalkenes 8–10 together with the corresponding 2,3-isomers 15–17 respectively. Treatment of compounds 7–10 with hydrogen peroxide in acetic acid gave the 1,2-bis(phenylsulfonyl)cycloalkenes 1–4.