美金刚衍生物的合成

盐酸美金刚(抗老年痴呆药物)与非甾体抗炎药(NSAIDs)反应合成了含NSAIDs药效单元的新美金刚衍生物,其结构经1H NMR, IR和MS表征.     

Photosensitization of Conjugated Bischalcone Derivatives. New T-Sensitizers

Photophysical properties and sensitizing activity in the polymerization of conjugated bischalcone and its derivatives of sensitizers of different classes: ketocoumarins, thioxanthenones, aminomethylene derivatives of heterocyclic thioketones, and selenium analogs of the latter, in deaerated solutions of N,N-dimethylacetamide in the presence of reducing agents were studied.     

Reactivity of Benzofuran Derivatives

This review presents a systematic and comprehensive survey of the chemical reactivity of benzofurans. These compounds are important intermediates for the synthesis of a variety of useful and novel heterocyclic systems that are otherwise difficult to obtain synthetically.     

Structure and Reactivity of Uracil Derivatives. 2. Ambident Nucleophilic Reactivity of 5-Diazouracil

On the basis of 3-21G type ab initio calculations we have studied all the possible complexes of 5-diazouracil with boron trifluoride. The most stable of these are the systems with the BF₃ coordinated at the 3, 9, and 10 positions of the heterocyclic molecule.     

Aza-ortho-Quinone Methide and Its Conjugated Acid: Reactivity,Stability and Acidity

Aza-o-quinone methides and their conjugated acids are reactive drug metabolites that might react with nucleophilic sites of DNAs and proteins to cause cancer or immune responses, and their reactivity with water is the key information to judge if these metabolites are harmful in living systems. For the first time, aza-o-quinone methide ( 1 ) and its conjugated acid ( 2 ) are observed by laser flash photolysis, and their reactivity, stability and acidity in water are determined.     

线型共轭Cx桥联双金属有机化合物

分子电子器件是近年来的一个热门课题。线型共轭Cx桥联双金属有机化合物是分子导线、分子开关等分子电子器件的模型化合物之一。本文介绍了线型共轭Cx桥联双金属有机化合物的结构、合成及光电性质。     

A Facile Synthesis of Indole-based Conjugated Derivatives

A novel synthetic method was developed for the preparation of indole-based conjugated derivatives with satisfied yields. By applying this strategy, a series of new compounds were prepared conveniently. All the obtained new indole derivatives were characterized by spectroscopic analyses, giving satisfactory data corresponding to their expected molecular structures.     

Structure and Reactivity of Uracil Derivatives. Thermodynamic Stability of 5-Diazouracil

The equilibrium position in the electrocyclization of certain model diazo compounds has been calculated using ab initio calculations based on RHF/6-31G with full optimization of the geometry. It was shown that on reducing the NN bond length the position of equilibrium is displaced towards the acyclic isomer. This effect is expressed to the greatest extent in -diazocarbonyl systems to which 5-diazouracil derivatives belong. An unusual polarized electron distribution was apparent for 5-diazouracil itself, which does not correspond with the classical Lewis structure.     

二噻吩衍生物的合成及其线性、非线性光谱性质

合成了一系列二噻吩衍生物类有机合物：5，5'-二（对－N，N－二甲胺基苯乙 烯基）－2，2'－二噻吩（BMSBT）与5，5'－二（对－N，N－二乙胺基苯乙烯基）- 2,2'-二噻吩（BESBT），5,5'-二（对N－环丁胺基苯乙烯基）－2,2'－二噻吩（ BBSBT），5,5－二（对－N－咔唑基苯乙烯基）2-2'－二噻吩（BCSBT），并测定了 其吸收光谱、单光子荧光光谱和双光子荧光光谱。BMSBT，BESBT和BBSBT的单光子 荧光参数存在的很强的、规则的溶剂效应，表明其激发态的分子可能有较大的极性 。在800nm fs激光下测得BMSBT与BESBT在560nm附近（与单光子荧光发射峰波长接 近的位置）有较强的上转换荧光发射，上转换荧光强度与激发能量之间较好的平方 关系表明了双光子激发的机理，这种上转换荧光被称为双光子荧光。用以光子荧光 法测得BMSBT和BESBT的双光子吸收截面分别为54*10~(-50)(cm~4·s)/photon和 102*10~(-50)(cm~4·s)/photon。     

Reactivity of Triphenylmethyl and Triphenylgermyl Derivatives of Lanthanides

Reactions of bis(triphenylmethyl)ytterbium and bis(triphenylgermyl)ytterbium with mercuric chloride, triphenylbismuth, iodine, tert-butyl alcohol, phenylacetylene, and cyclopentadiene were studied. The higher reactivity of the former compound in these reactions is explained by that the chemical bond in it is ionic, whereas in its germyl analog, covalent.     

Water Oxidation with Cobalt-Loaded Linear Conjugated Polymer Photocatalysts

The first examples of linear conjugated organic polymer photocatalysts that produce oxygen from water after loading with cobalt and in the presence of an electron scavenger are reported. The oxygen evolution rates, which are higher than for related organic materials, can be rationalized by a combination of the thermodynamic driving force for water oxidation, the light absorption of the polymer, and the aqueous dispersibility of the relatively hydrophilic polymer particles. We also used transient absorption spectroscopy to study the best performing system and we found that fast oxidative quenching of the exciton occurs (picoseconds) in the presence of an electron scavenger, minimizing recombination.     

Synthesis and Reactivity of New Pentacoordinated Phosphoenolpyruvate Derivatives

Abstract

Pentaoxyphosphoranes are closely related as intermediates to the biologically important phosphate ester reactions. Thus, the hydrolysis of phosphoenolpyruvate 1, a strong phosphorylating agent, proceeds most probably via the formation of the cyclic acyloxyphosphorane 2.     

Linear Conjugated Coordination Polymers Containing Eight-Coordinate Metal Centers

Two linear coordination polymers are reported in which conjugated organic ligands and nonrigid eight-coordinate metal centers are linked to form macromolecules with molecular weights of greater than 10⁴ Daltons. The tungsten(IV) chelate is an inert low-spin d² species with four oxygen and four nitrogen donors per metal with two bidentate blocking ligands and one bis-bidentate bridging ligand. The zirconium(IV) chelate is rendered inert through the use of a bis-quadridentate Schiff-base ligand. Future possibilities and potential uses are also discussed.     

Novel Terpyridine Conjugated Nitrogen Mustard Derivatives: Synthesis,Spectral Properties,and Anticancer Activity

Russian Journal of General Chemistry - A series of 2,2′:6′,2′-terpyridine conjugated nitrogen mustard derivatives with structurally symmetrical character and rather small...     

Anilinolysis of Picryl Benzoate Derivatives in Methanol: Reactivity,Regioselectivity, Kinetics,and Mechanism

The reaction of picryl benzoate derivatives 1a–g with aniline in methanol proceeds through CO? O and Ar? O bond cleavage pathways. Furthermore, the reactivity of these esters toward anilinolysis is correlated to the energy gap between highest occupied molecular orbital aniline and lowest unoccupied molecular orbital of each ester. The regioselectivity of acyl? oxygen versus aryl? oxygen cleavage is also discussed. The overall rate constants k_tot split into k_{CO? O} (the rate constant of acyl‐oxygen cleavage) and k_{Ar? O} (rate constant of aryl‐oxygen cleavage). The CO? O bond cleavage advances through a stepwise mechanism in which the formation of the tetrahedral intermediate is the rate‐determining step. The Ar? O bond cleavage continues through a S_NAr mechanism in which the departure of the leaving group from the Meisenheimer complex occurs rapidly after its formation in the rate‐determining step.     

邻异丙硫基苯甲酰基和苯硫甲基铁衍生物的合成与反应

利用异丙基苯硫醚与丁基锂反应后,再依次与羰基铁和碘反应制得了碘桥双核邻异丙硫基苯甲酰基铁配合物[（o-ⁱPrS） C₆H₄COFe（CO）₂I]₂,而苯甲硫醚类似的反应却仅得到单核苯硫甲基铁配合物C₆H₅SCH₂Fe（CO）₃I。当与亲核试剂作用时,这2个化合物表现出显著不同的反应活性。如双核配合物[（o-ⁱPrS） C₆H₄COFe（CO）₂I]₂与2-吡啶硫醇钠（PySNa）反应得到单核配合物（o-ⁱPrS） C₆H₄COFe（CO）₂（SPy）,但单核配合物C₆H₅SCH₂Fe（CO）₃I与PySNa反应导致其分解。另一方面,单核配合物C₆H₅SCH₂Fe（CO）₃I与三苯基膦（PPh₃）反应得到羰基取代配合物C₆H₅SCH₂Fe（CO）₂（PPh₃） I,但是双核配合物[（o-ⁱPrS） C₆H₄COFe（CO）₂I]₂类似的反应却导致其分解,没有获得可表征的化合物。所有新合成的化合物都通过了核磁与红外光谱的表征,它们的结构也获得了X射线单晶衍射的确证。     

Synthesis of Polysubstituted Pyrrolizidines from Proline Derivatives and Conjugated Nitroolefins

The stereochemistry of 1,3-dipolar cycloaddition of azomethine ylides derived from aromatic aldehydes and i-proline alkyl esters with several nitroolefins was investigated. Cyclic and acyclic nitroolefins add to the anti form of the ylide in a highly diastereoselective but poorly regioselective manner to give pyrrolizidine derivatives. In a few cases, the stereochemical results strongly support a stepwise mechanism.     

Comparative Study of Photochromic Ferrocene‐Conjugated Dimethyldihydropyrene Derivatives

The photochemical properties and the mixed‐valence state of bis(ferrocenylethynyl)benzodimethyldihydropyrene ( 1 ) and other benzodimethyldihydropyrene (BzDHP) derivatives were investigated to understand the reversible photoswitching in the electronic communication of 1 . Absorption spectra of 1 were characterized by UV/Vis spectroscopy and calculated by using time‐dependent density functional theory (TD‐DFT), and the d orbitals of the ferrocene (Fc) moieties were shown to contribute to the occupied valence orbitals that were responsible for the photochromic behavior. 1 exhibited reversible photoisomerization in THF; however, photochromic behavior was not observed in dichloromethane. Analysis of redox potentials showed that the mixed‐valence state of 1 was more stable in dichloromethane than in THF. This is consistent with the observation that chemical oxidation led to an intervalence charge‐transfer (IVCT) band between the Fc moieties in the mixed‐valence state of 1 in dichloromethane, whereas such a band was not observed for one‐electron‐oxidized 1 in THF. Bis(pentamethylferrocenylethynyl)benzodimethyldihydropyrene ( 2 ) did not show photochromic behavior even in THF. The mixed‐valence state of 2 was much less stable than that of 1 in dichloromethane, and no obvious IVCT band was observed for one‐electron‐oxidized 2 in dichloromethane. The difference in the redox contribution of Fc and pentamethylferrocene (Me₅Fc) to BzDHP played an important role for these redox and photochromic behaviors; this was supported by analysis of valence orbital energies from DFT calculations. Designing molecules that connect redox centers through the use of a photochromic linker with a redox potential close to that of the redox centers could constitute a useful approach for the production of photochromic redox‐active metal complexes with strong electronic communication.