Application of N,N‐bis(diphenylphosphino)aniline palladium(II) complexes as pre‐catalysts in Heck coupling reactions

Palladium(II) complexes with N,N‐bis(diphenylphosphino)aniline ligands catalyse the Heck reaction between styrene and aryl bromides, affording stilbenes in good yield. The structures of two of the complexes used as pre‐catalysts have been determined by single‐crystal X‐ray diffraction. Copyright © 2007 John Wiley & Sons, Ltd.     

基于发光二极管探测器的太阳光度计的研究

介绍了一种采用商用发光二极管作为探测器的新型太阳光度计。阐述了系统的结构以及该仪器在监测气溶胶光学厚度领域的应用,并与传统的太阳光度计进行了对比试验。试验表明,两种仪器具有很好的一致性。     

含CdS的聚碳酸醋薄膜的光电效应

近来有一些学者从理论或实践上探讨了模拟植物光合作用的光电化学膜体系用于太阳能转换的可能性。这种体系的核心是一个具有光活性的膜,把两个含有氧化还原偶的水溶液分隔开;当膜受光照时在膜里产生电荷(电子和空穴)的分离,电子到膜的一侧引起一个还原反应而空穴到膜的另一侧引起一个氧化反应。本文用一种聚碳酸酯的透明薄膜(商品名Nuclepore membrane),膜上已用中子照射的方法打好了大小和分布都很均匀的大量微孔,然后在这些微孔里形成CdS沉淀。这样得到的光活性膜体系,改性后在光照时能     

Heterocyclic diazo compounds as starting materials in organic synthesis (review)

Data on the structures and reactions of heterocyclic diazo compounds that lead to the formation of new heterocyclic systems as a result of intra- or intermolecular cyclization and rearrangements are systematized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 579–603, May, 1980.     

新型手性Salen双核锌配合物的分子识别研究

合成了新型手性Salen配体（H3L）及新型手性Salen双核锌配合物（主体）.通过研究主体对咪唑类客体及氨基酸酯类客体的分子识别行为,测定了这些配位反应的缔合常数.主体对咪唑类客体分子识别的缔合常数顺序为:K(Im) >K(2-MeIm) >K(2-Et-4-MeIm).主体对氨基酸酯类客体分子识别的缔合常数顺序为:K(LeuOCH3) >K(ValOCH3) >K(AlaOCH3) >K(SerOCH3),配位数均为2.主体与D、 L型氨基酸酯分子识别反应在不同温度下的缔合常数结果表明,随着温度的升高,对映选择性下降.实验发现反应体系中存在焓熵补偿关系. CD光谱的研究结果也反映了主体对不同客体识别能力的差异.     

Synthesis of Novel <Emphasis Type="Italic">D</Emphasis>-<Emphasis Type="Italic">Seco</Emphasis>-Pregnenes

Summary. A new synthetic route was developed for the preparation of trans-3-hydroxy-16,17-seco-pregna-5,17(20)-dien-16-al, using Grob fragmentation as the key step. This seco-steroid contains a formyl group and an unsaturated side-chain in a sterically favourable position, and is therefore a promising starting material for the synthesis of novel condensed steroid heterocycles.Received March 22, 2003; accepted April 22, 2003 Published online September 25, 2003     

An approach to the tricyclic core of madangamines based upon a biogenetic scheme

[reaction: see text] A short synthesis of intermediates possessing the tricyclic core of natural madangamines, bioactive alkaloids found in marine sponges, is described. The key reaction entails the condensation of the sodium salt of diethylacetonedicarboxylate with a dihydropyridinium salt derivative. This new approach is modeled on a biogenetic proposal linking madangamines to ircinals, related alkaloids occurring in sponges of the same order.     

PHOTOSENSITIZATION SYSTEMS OF COVALENTLY LINKED PHTHALOCYANINE COMPLEXES IN BOTH BILAYER LIPID MEMBRANES AND TIN OXIDE PHOTOVOLTAIC CELL

Abstract Zinc phthalolocyanine photosensitized donor-acceptor systems for light energy conversion and for the design of photoelectrochemical molecular devices are presented. Covalently linked phthalocyanine complexes were incorporated in bilayer lipid membranes (BLM) and deposited on SnO₂ transparent electrodes. Their photovoltages were measured and compared. It has been found that a more favorable orientation and closer proximity are attained in the diad compounds between the donor (phthalocyanine)-acceptor (anthraquinone) pair than in the reference compound for efficient light-induced charge separation and transfer. The triad compound is the best among all tested compounds. The decrease in the fluorescence yield and lifetime induced by quinones was examined and the apparent electron-transfer rate constants were calculated.     

Neighbouring group participation in formation of condensed azines. Formation of pyrazolo(3,4-b)pyrazines,isoxazolo(4,5-b)pyrazines and isothiazolo(5,4-b)pyridine

Pyrazine- and pyridinecarboxamidoximes with an amino, potentially tautomeric hydroxy or mercapto group inortho position could be transformed in the appropriate condensed azines. In this manner, representatives of pyrazolo(3,4-b)pyrazine, isoxazolo(4,5-b)pyrazine and isothiazolo(5,4-b)pyridine ring system were synthesized and some transformations investigated.Presented in part at the 8th International Congress of Heterocyclic Chemistry, Graz, 1981.