An Efficient and Facile Synthesis of Quinoxaline Derivatives Catalyzed by KHSO4 at Room Temperature

Summary. A facile synthesis of quinoxaline derivatives catalyzed by KHSO₄ in very high yields at room temperature is reported.     

纤维素衍生物手性固定相研究进展

本文从用作手性固定相的纤维素衍生物种类、纤维素衍生物手性固定相制备方法及其在高效液相色谱中的应用三个方面介绍了国内外近年来的研究进展,并展望了该领域今后的研究方向。     

Synthesis of (trichloromethyl)organosilanes by catalytic decarboxylation of (trichloroacetoxy)organosilanes

A method for preparing (trichloromethyl)organosilanes by the catalytic decarboxylation of the corresponding trichloroacetoxysilanes RMe₂SiOC(O)CCl₃ (R = Me, ClCH₂, Ph, Me₃Si, and H) has been developed. The method involves heating the starting compounds without a solvent in the presence of a catalyst (quaternary ammonium salts or potassium salts with the addition of crown ethers). Tertiary amines (Et₃N, Bu₃N) catalyze this reaction only when heating is carried out in donor aprotic solvents (THF, acetonitrile) in the presence of oxygen. Thermal decomposition of (trichloroacetoxy)organosilanes, in contrast to catalytic decarboxylation, begins at a higher temperature and yields a mixture of products.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 150–153, January, 1995.     

3-(3′-吡啶基)-6-芳基-1，2，4-三唑并[3，4-b]-1，3，4-噻二唑衍生物基态和激发态性质

用密度泛函B3LYP方法对3-(3'-吡啶基)-6-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑衍生物(芳基为苯基、3-吡啶基和苯乙烯基)进行基态几何构型全优化,计算分子的电离势I_p和电子亲和势E_A等相关能量,并用Zerner间略微分重叠(ZINDO)和含时密度泛函(TDDFT)方法计算吸收光谱,用单组态相互作用方法(CIS)优化三种化合物分子的S_1激发态结构,分析其能量与发射光谱的关系,计算溶剂中分子的吸收和发射光谱,并与实验结果对照.计算结果表明,从3-(3'-吡啶基)-6-苯基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑分子(化合物A)到3-(3'-吡啶基)-6-(3'-吡啶基)-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑分子(化合物B)以及3-(3'-吡啶基)-6-对乙烯苯基-1,2,4-三唑并[3,4-b]- 1,3,4-噻二唑分子(化合物C)的电子亲和势依次增大,愈来愈容易接受电子,吸收光谱和发射光谱红移.     

The benzene ring as a dipolarophile: Reactions of monosubstituted benzenes with tetracyanoethylene oxide

Summary The reaction of tetracyanoethylene oxide on one hand and toluene, chlorobenzene, fluorobenzene, anisole, and nitrobenzene, on the other, has been studied. Toluene and the halogenobenzenes yield mixtures of monoadducts, anisole yieldp-methoxyphenylmalononitrile and its dimer and nitrobenzene does not react. These results are discussed with the help of a qualitative orbital model.¹H-NMR analysis of some monoadducts has been carried out.

---

Der Benzolring als Dipolarophil: Reaktionen monosubstituierter Benzole mit Tetracyanoethylenoxid

Zusammenfassung Es wurden die Reaktionen von Tetracyanoethylenoxid mit Toluol, Chlorbenzol, Fluorbenzol, Anisol und Nitrobenzol untersucht. Toluol und die Halogenbenzole ergaben Mischungen von Monoaddukten, Anisol ergabp-Methoxyphenylmalononitril und sein Dimer, Nitrobenzol zeigte keine Reaktion. Diese Resultate werden mit Hilfe eines qualitativen Orbitalmodells diskutiert. Die Analyse einiger Monoaddukte erfolgte mittels¹H-NMR-Analyse.

     

Electronic structure and conformational flexibility of 1,4-dihydroazines and their 4-ylide derivatives

The conformational flexibility of 1,4-dihydropyridine, 1,4-dihydropyrimidine, 1,4-dihydropyridazine, 1,4-dihydro-1,3,5-triazine, and their 4-oxo, imino, and methylene derivatives was studied by the semiempirical quantum-chemical AM1 method. It was demonstrated that the replacement of the methylene group in the dihydroazine ring by the exocyclic double bond results only in an increase in the rigidity of the heterocycle rather than leading to a loss of its conformational flexibility. It was suggested that nonplanar conformations of rings in ylide derivatives are stabilized by the nonaromatic cyclic -system. Introduction of the exocyclic double bond does not cause a substantial change in the -electronic structure of the heterocycle. The aromaticity indicesI ₆ andI ₆() were calculated. The correlation between these indices and a change in the energy upon bending of the heterocycle was established.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No 8 pp 1938–1941, August, 1996.     

各种氨基酸衍生物在Chirasil—Val固定相上的气相色谱分离

本文叙述氨基酸及其对映体的全氟酰基烷基脂(O-异丙基、-异丁基、-正丁基;N(O,S)-三氟乙酰基,TFA、-七氟丁酰基,HFB)在Chirasil-Val上的洗脱特性。随烷基取代增大,保留时间增加;用HFB代替TFA,对映体的分离因子降低。此外,DL-氨基酸与另丁醇衍生,生成的对映及非对映衍生物在Chirasil-Val上可拆分成四个色谱峰。     

Mesoporous silica nanospheres with the ability of photo-driven releasing sandela 803 for the application to wallpaper

Mesoporous silica nanospheres loaded with sandela 803 (S803@MS-S) are prepared for application to wallpaper. The nano-fragrance has high encapsulation efficiency and property of photo-driven release.     

Synthese und Geruch von (Z)-Dehydro-homo-β-santalol

Summary Guided by molecular modeling studies, the synthesis of the title compound is described. The organoleptic evaluation proved the predicted real sandal like odour of (Z)-dehydro-homo--santalol.

Aus den Diplomarbeiten von C.P. (1991), I.P. und B.Ö. (1992), Universität Wien     

1,4-苯醌衍生物的合成、氧化还原电位和生物活性的研究

合成了一系列具有不同的醌环结构(醌环上的取代基不同,如甲基、甲氧基、氢、氯和溴,或取代基的排列位置不同)的6-正癸基-1,4-苯醌衍生物。系统地研究了它们的结构、氧化还原电位和在线粒体琥珀酸-细胞色素 c 氧化还原晦中生物功能的关系。