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关键词： 超临界流体   绿色化学   有机合成   环境保护  

摘要： 简要介绍了绿色化学的内涵及研究方向,阐述了超临界流体独特的物理化学性质,重点介绍了目前国内外超临界流体CO_2在催化氢化、聚合反应、酶催化反应和金属有机反应等有机合成中应用的新成果.它在绿色化学反应方面的研究具有很大的潜在优势.

ISBN: (纸本)7040138360

关键词： transition metals   organic synthesis   catalysis  

摘要： A review with 1717 references to transition metal-catalyzed or mediated reactions and functional group preparations. (C) 2004 Elsevier B.V. All rights reserved.

关键词： Mannich base   o-quinone methide   o-naphthoquinone methide   naphthol   dibromomethane   diethylamine  

摘要： The salt formed from the reaction of dihalomomethane and diethylamine reacted with phenolic compounds to give the corresponding Mannich bases in modest to good yields. As for the relative rates and yields are in the following order: CH2Br2 > CH2Cl2. The CD2Cl2 is also applicable to prepare the deuterated analogues. At higher temperature, the elimination of diethylamine from Mannich base occurred to give the corresponding o-quinone methide intermediate, which was then trapped by another phenolic compound to give bis(2-hydroxy-1-aryl)methanes.

关键词： alcohols   nucleosides   phosphonates   phosphonylation   ribozyme   spiro compounds  

摘要： The phosphonylation by oxirane/phosphorous acid is characterized by formation of spirophosphorane, which provides the active intermediate in. the reaction, beta-hydroxyalkyl alkylene phosphite. Here, we demonstrate that a well-known and readily accessible spirophosphorane, 2lambda(5)-2,2'spirobi[1,3,2-benzodioxaphosphole] can be used as convenient and effective phosphonylating agent in similar reaction. The easily detectable primary 3-phenylpropyl H-phosphonate, as well as 5'-O-tritylthymidyl, 4-N-benzoyl-5'-O-trityl-deoxycytidyl, 5'-O-trityl-deoxycytidyl, 6-N-benzoyl-5'-O-trityl- deoxyadenosyl 5'-O-trityluridyl, and 2',3'-isopropylidene-uridyl H-phosphonates were prepared using a simple and straightforward procedure. Our results provide all interesting example of the potential and the limitations of a synthetic approach utilising reaction of leaving of diol system.

关键词： building blocks   molecular diversity   small ring systems   synthetic methods   titanium  

摘要： A well reproducible and inexpensive preparation of the cyclopropylideneacetates 2-4 has been developed. The key intermediate 2-(1'-mesyloxycyclopropyl)acetic acid (8), produced either from methyl phenylacetate (1) or 3,3-dimethoxypropionate (5-Me) and 3,3-diethoxypropionate (5-Et) in a sequence of Kulinkovich reductive cyclopropanation, mesylation and oxidative cleavage or cleavage and oxidation, respectively, was either converted to the benzyl ester 11b, or chlorinated (brominated) via the in situ formed acid chloride. The alpha-chloro- 12a and alpha-bromo ester 12b were dehydromesylated by treatment with triethylamine to furnish methyl 2-chloro-2-cyclopropylideneacetate (3-Me) and the 2-bromo analogue 4-Me with an overall yield of 68% (65%, 68%) and 52% (49%, 51%) respectively, starting from 1 (5-Me, 5-Et). The parent benzyl cyclopropylideneacetate 2-Bn was obtained by dehydromesylation of 11b with potassium t-butoxide in t-butyl methyl ether with an overall yield of 60% (57%, 9%) from I (5-Me, 5-Et).

关键词： gold catalysis   transition-metal catalyst   gold-catalysts  

摘要： The catalysis of organic reactions by gold-catalysts has received in the past only little attention because of the preconceived opinion that gold is expensive and inert. The successful application of supported gold catalysts to pollution abatement changed this assessment and spurred on the explosion of interest in gold catalysis towards organic synthesis. Supported Au catalyst and homogeneous gold(III)-catalysts are effective in oxidation processes based on the most attractive oxidant. O-2/air, that proceed at a satisfactory rate at room temperature. selectively. and without rapid catalyst decomposition. Gold (III) salts are very effective catalysts for amination reaction of carbonyl compounds. The regio-/chemoselective interaction to the acetylenic bond is another of the more interesting features of gold catalysis. Activation of alkynes towards nucleophilic attack proved that gold salts are soft, exceptionally carbophilic Lewis acids. The dual role of Au(III) as a Lewis acid and as a transition-metal catalyst accomplished the synthesis of a variety of heterocycles through domino reactions.

关键词： Hydrocarbons   Aromatic compounds   Organic polymers   Organic reactions   Polymers  

摘要： A series of norbornene-based resin beads were obtained by aqueous suspension ring-opening metathesis polymerization (ROMP) and used as polymeric supports for organic synthesis. These resins were prepared from norbornene, norborn-2-ene-5-methanol, and cross-linkers such as bis(norborn-2-ene-5-methoxy)alkanes, di(norborn-2-ene-5-methyl)ether, and 1,3-di(norborn-2-ene-5-methoxy)benzene. The resulting unsaturated ROMP (U-ROMP) resins containing olefin repeat units were chemically modified using hydrogenation, hydrofluorination, chlorination, and bromination reactions to produce saturated ROMP resins with different chemical and physical properties. The hydrogenated ROMP (H-ROMP) resin was found to be highly resistant to acidic, basic, Lewis acid, and Birch reduction conditions and was assessed as a polymeric support in a series of solid-phase synthetic applications. The H-ROMP resin was found to have superior performance compared to polystyrene-divinylbenzene (PS-DVB) copolymers in aromatic nitration and acylation reactions. In a conventional five-step solid-phase synthesis of a hydantoin, similar results were obtained for both the H-ROMP and PS-DVB resins. The U-ROMP resin was also shown to be effective in the solid-phase syntheses of benzimidazoles and benzimidazolones.

关键词： 二碘化钐   三氟甲磺酸镱   双(三氯甲基)碳酸酯   氯甲酸苯酯   氯甲酸-1,3-噻唑基-5-甲酯  

摘要： 该论文共分三章:1.二碘化钐促进的有机反应在有机合成中的应用;2.三氟甲磺酸镱催化的有机反应在有机合成中的应用;3.双(三氯甲基)碳酸酯替代光气在氯甲酸酯合成中的应用.第一章,首先我们综述了近几年来二碘化钐促进的有机反应在有机合成中的应用.然后研究了二碘化钐促进的邻硝基N,N-二乙基苯磺酰胺与腈发生的分子间交叉还原偶联反应,一步合成了2H-1,2,4-苯并噻二嗪-1,1-二氧化物.第二章,首先我们综述了近几年来三氟甲磺酸镱催化的有机反应在有机合成中的应用.然后研究了三氟甲磺酸镱催化的胺和乙酸乙酯的反应,从而合成了乙酰苯胺类化合物.第三章,首先我们介绍了光气的理想替代品——双(三氯甲基)碳酸酯的物理化学性质及其在医药中间体合成中的应用.然后研究了双(三氯甲基)碳酸酯在合成氯甲酸苯酯和氯甲酸-1,3-噻唑基-5-甲酯的应用.以上所研究的反应具有原料易得,操作简便,反应条件温和,产率较高,以及原子经济性高等优点.

关键词： Biginelli反应   有机合成   二氢嘧啶酮类化合物   药理活性  

摘要： 介绍了Biginelli反应及其在有机合成中的应用