Chemistry and Structure of Diterpene Compounds of the Kaurane Series: VI. Isosteviol Esters

Esterification with alcohols and diols of (4,8,13)-13-methyl-16-oxo-17-norkaurane-18-carboxylic acid chloride prepared by treatment of the acid (isosteviol) with thionyl chloride yields the corresponding esters. The molecular and crystal structures of a series of esters were determined by single crystal X-ray diffraction. The diethylene glycol diester in the crystal has a tweezer structure with an intramolecular cavity. The supramolecular structure of some isosteviol derivatives in the crystal is characterized by alternation of lipophilic and hydrophilic regions.     

Chemistry and Structure of Diterpene Compounds of the Kaurane Series: VIII. Azomethines Derived from Isosteviol

(4,8,13)-13-Methyl-16-oxo-17-norkaurane-18-carboxylic acid (isosteviol) and its methyl ester were reacted with benzylamine and hydroxylamine to obtain the corresponding E-stereoisomeric 16-ketimines. Isosteviol benzylimine and oxime form individual 1:1 H-bonded complexes with methanol and water, respectively.     

Chemistry and Structure of Diterpene Derivatives of the Kaurane Series: V. Isosteviol Anhydrides

(4,8,13)-13-Methyl-16-oxo-17-norkaurane-18-carboxylic acid (isosteviol) anhydride is synthesized, which is a first representative of bisditerpene compounds of the kaurane series. The structures of the anhydride and isosteviol chloride were studies by X-ray diffraction and quantum chemistry (AM1).     

Chemistry and Structure of Diterpene Compounds of the Kaurane Series: IX. Electrochemical Reactions of Isosteviol and Its Derivatives

The keto group in (4,8,13)-13-methyl-16-oxo-17-norkaurane-18-carboxylic acid (isosteviol) is not polarographically reduced in DMF. Isosteviol methyl ester and oximes, too, are not reduced under these conditions. Isosteviol oxime is oxidized electrochemically or with lead dioxide, yielding iminoxyl radical.     

Chemistry and Structure of Diterpene Compounds of the Kaurane Series: IV.1 Acylation of Reduction Products of the Isosteviol Keto Group

Acetylation with acetic anhydride of (4,8,13)-16-hydroxy-13-methyl-17-norkaurane-18-carboxylic acid and its methyl ester, obtained by reduction of isosteviol and (4,8,13)-18-methoxycarbonyl-13-methyl-16-oxo-17-norkaurane, respectively, gives rise to (4,8,13)-16-acetoxy-13-methyl-17-norkaurane-18-carboxylic acid and (4,8,13)-16-acetoxy-18-methoxycarbonyl-13-methyl-17-norkaurane. The molecular and crystal structures of the compounds were established by X-ray diffraction.     

Chemistry and Structure of Diterpenoids: X. Isosteviol Amides

Acylation of amino alcohols with isosteviol chloride, depending on the reactant ratio, leads to formation of either bis-isosteviol derivatives or N-acylation products. Reactions of aromatic diamines with 2 equiv of isosteviol chloride give the corresponding N,N′-bis(isostevioyl) derivatives.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 2, 2005, pp. 276–281.Original Russian Text Copyright © 2005 by Al’fonsov, Kataev, Strobykina, Korochkina, Kovylyaeva, Bakaleinik, Beskrovnyi, Gubaidullin, Litvinov, Musin.For communication IX, see [1].     

Molecular Complexes of Iodine with Aromatic Compounds

The correlation between the spectral characteristics of molecular complexes of iodine with various benzene derivatives and the ionization potentials of the donor molecules is discussed. The isomerism of these complexes, determined by the structure of the electronic level with which the orbital of the acceptor interacts and by the steric structure of the donor molecules, is revealed.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 3, 2005, pp. 438–444.Original Russian Text Copyright © 2005 by Pryalkin.     

手性卟啉-尼古丁化合物及其Mn（Ⅲ）配合物的合成

手性卟啉-尼古丁化合物及其Mn（Ⅲ）配合物的合成     

Chemistry of Diazopolycarbonyl Compounds: VII. Reactions of 3-Diazo-2-oxopropionic Acid Derivatives with Aroylhydrazines

3-Diazo-2-oxopropionic acid esters and amides react with benzoic and salicylic acid hydrazides to afford 2,3-bis(aroylhydrazono)propionic acid esters and amides having an osazone structure.     

一类芳香族偶氮化合物的合成及表征

采用重氮偶合反应合成了一系列不同对位取代的4-[N，N-(二羟乙基)]氨基偶氮苯化合物，其结构用元素分析，IR，1HNMR，DSC，DSC等进行表征和确认。     

Charge Transfer Complexes of 1,3,6-Trinitro-9,10-phenanthrenequinone with Polycyclic Aromatic Compounds

Understanding the interactions of organic donor and acceptor molecules in binary associates is crucial for design and control of their functions. Herein, we carried out a theoretical study on the properties of charge transfer complexes of 1,3,6-trinitro-9,10-phenanthrenequinone (PQ) with 23 aromatic π-electron donors. Density functional theory (DFT) was employed to obtain geometries, frontier orbital energy levels and amounts of charge transfer in the ground and first excited states. For the most effective donors, namely, dibenzotetrathiafulvalene, pentacene, tetrathiafulvalene, 5,10-dimethylphenazine, and tetramethyl-p-phenylenediamine, the amount of charge transfer in the ground state was shown to be 0.134−0.240 e⁻. Further, a novel charge transfer complex of PQ with anthracene was isolated in crystalline form and its molecular and crystal structure elucidated by single-crystal synchrotron X-ray diffraction.     

Chemistry of Polypyridine Ruthenium Complexes: VII. Electronic Structure and Photochemistry of cis-[Ru(2,2'-bpy)2(L)(Cl)]+ Complexes

The electronic absorption spectra and photochemical behavior of the complexes of cis-[Ru(bpy)₂ · (L)(Cl)]⁺ (bpy is 2,2'-bipyridyl) with pyridine (L = py) and 4-substituted pyridines [L = methyl-, amino-, and cyanopyridine, and 4,4'-bipyridyl (bipy)]. Photoirradiation of acetonitrile solutions of the complexes results in substitution of ligand L by a solvent molecule. A correlation was revealed between the photolysis quantum yield and the coordination-induced ligand L-to-metal charge transfer.     

芳香氮化物-CHCl3系列复合物密度泛函法研究

报道对芳香氮化物吡咯(C4H5N)、苯胺(C6H5NH2)、对位氯代吡啶(C5H4NCl)、吡啶(C5H5N)及吡咯负离子(C4H4N-)与三氯甲烷(CHCl3)形成的系列弱作用复合物的理论计算结果.把复合物看作是一个超分子,在密度泛函B3LYP/6-311G(d,p)的水平上进行计算,探讨该系列复合物的稳定性规律、电荷转移及主要几何参数变化等规律.计算结果表明:此类芳香氮化物与三氯甲烷(CHCl3)可形成一系列弱化学作用复合物,特别是带负电荷的芳香氮化物可与CHCl3形成较稳定的复合物.形成复合物的过程包含着电荷转移,该系列复合物的稳定性与广义H键距离的变化规律相一致,与电荷转移量的变化规律大体一致.     

Mild and Efficient Nitration of Aromatic Compounds Mediated by Transition-Metal Complexes

Aromatic compounds were efficiently nitrated under facile reaction conditions by employing 69% nitric acid catalyzed by transition-metal complexes such as [Co(NH₃)₅Cl]Cl₂, [Cu(NH₃)₄]SO₄, Mn(acac)₃, [Ni(NH₃)₆]Cl₂, [Ni(en)₃]S₂O₃, and Hg[Co(SCN)₄]. The reaction was completed smoothly at room temperature and afforded corresponding mono-nitro derivatives in quantitative yield. This new method offers efficient and facile regioselective mononitration of aromatic compounds.

Enantioselective Single-Crystal-to-Single-Crystal Photodimerization of Coumarin and Thiocoumarin in Inclusion Complexes with Chiral Host Compounds

An intermolecular enantioselective photoreaction by a single-crystal-to-single-crystal transformation has been carried out for the first time, as is evident from X-ray structure analysis and X-ray powder diffractometric studies. This reaction, the dimerization of the title compound to cyclobutane derivative 1 (X=O, S), provides a good example for studying the mechanism of topochemical reactions in the crystal.     

系列烯基化芳香杂环化合物的合成及结构表征

报道了一个简单、 高选择性合成烯基化芳香杂环化合物的反应体系. 在钯的催化作用下, 以乙酸/乙酸酐或四氢呋喃为溶剂, 芳香杂环化合物与烯基化试剂进行交叉脱氢偶联, 合成了系列具有潜在光学活性的烯基化芳香杂环化合物, 确定了最佳反应条件. 采用紫外光谱、 核磁共振氢谱和X射线单晶衍射对目标化合物进行了表征, 并对反应机理进行了探讨.     

二烷基胺基锂对α-芳族酮酸手性钛盐的不对称还原反应

将手性配体通过交换反应引入α-芳族酮酸钛盐，以二烷基胺基锂为还原剂进行不对称还原反应得到α-羟基羧酸，对映体过量率在8.5%～24.9%之间。     

Supplementary Observations on the Chemistry of the Alkaloids of Berberine Series and Related Compounds. III. Fluorescence Spectra of the Alkaloids of Berberine Series and Their Related Compounds

The absorption maxima of the fluorescence spectra of the berberine series alkaloids are broadly distributed between 360 and 560 mμ. The fluorescence spectra of most substances of this series are very monotonous one having a single peak, the spectra of tetrahydrocoptisine and tetrahydroepiberberine are quite exceptional and consist of two wavy bands. The introduction of the auxochrome group into the molecule of “proto” compounds causes the decreasing of the fluorescence intensity and this effect is strongest in case of transition from protoberberine to berberine. That, tetrahydropalmatine does not show the distinct fluorescence spectrum band is the only incomprehensible fact.