合成方法对MCM-22分子筛的结构、性质及催化性能的影响

在水热条件下分别以动态法和静态法合成了高纯度和高结晶度的MCM-22分子筛.采用N2吸附、XRD、TEM和FTIR等方法研究了制备方法对分子筛的结构及性质的影响.结果表明,动态法合成的MCM-22比静态法合成的分子筛的晶粒小,酸量低.在丙酮一步法合成甲基异丁基酮反应中,静态条件下合成的MCM-22为载体的催化剂的丙酮转化率较高,这是由于该分子筛的酸量较高所致.而MIBK的选择性则呈相反趋势,这可能与动态条件下合成的分子筛粒径小、孔道短有关.     

氨基二硫代甲酸酯类化合物的合成及生物活性研究进展

氨基二硫代甲酸酯类化合物由于具有广泛的生物活性,其合成方法和药理活性的研究已成为有机化学和药物化学领域研究的热点.在合成方法方面,对在强碱条件下、弱碱条件下、以水为溶剂、以离子液为溶剂和无溶剂条件下合成该类化合物的方法进行了综述.在生物活性方面,对该类化合物在治疗慢性酒精中毒、抗氧化、抗病毒、抗菌、抑制胆碱酯酶、肿瘤预防以及抗肿瘤方面的作用进行了综述     

酶催化生物可降解聚酯的合成与研究进展

生物可降解聚酯是一种新型高分子聚合材料,可通过发酵、化学方法和酶催化来合成.本文综述了酶催化下通过缩聚、酯交换、内酯开环聚合等方法合成此类聚酯.酶催化合成生物可降解聚酯是一种新型的技术,可以在温和条件下高效合成,有着传统方法难以比拟的优势.     

水促进的三组分PBM反应合成三级胺

首次报道了甲醛衍生的胺缩醛和芳基硼酸在水的促进下,可以在没有催化剂的条件下高效的合成三级胺.在此基础上建立了一种利用多聚甲醛,二级胺和芳基或杂环硼酸合成三级胺的高效合成方法.此反应条件温和,操作简单,具有很好的底物适应性,目标产物的收率最高可达93%.     

由有机盐简便合成不饱和醛、酮、酰胺以及有关天然产物

本文报道有机盐和各种不同的醛在固-液相转移条件下, 以碳酸钾为碱, 简便合成共轭不饱和醛、共轭不饱和酮以及共轭不饱和酰胺.以此合成方法, 还合成了一些具有生物活性的天然产物. 该合成方法操作简便, 反应条件温和, 产物高度立体选择性, 产率优良, 这为多烯醛, 多烯酮, 多烯酰胺以及有关天然产物的合成提供了实用途径.     

羟基磷酸铜的快速绿色合成

通过研究羟基磷酸铜的合成条件, 提出了一种快速绿色的新合成方法, 在不使用有机胺和减少磷酸使用量的条件下, 降低水热晶化的温度, 缩短了合成所需要的时间. 同时对所制得样品的苯酚羟化催化活性进行了表征.     

一锅法串联反应合成巯基烟酰胺类衍生物

以巯基烟酸和胺为起始原料,通过一锅法三步串联反应,合成了一系列巯基烟酰胺类衍生物,探索出了一种在温和条件下高效合成巯基烟酰胺类衍生物的方法,解决了以往巯基烟酰胺合成步骤繁琐、条件苛刻、产率低等问题.在未来生物活性分子和药物分子合成上有潜在的应用价值.     

芳香磺酰肼与胺通过铜催化氧化偶联合成芳香磺酰胺（英文）

报道了在铜催化的条件下,芳香磺酰肼与各种胺氧化偶联合成芳香磺酰胺化合物.相比于传统的合成磺酰胺方法,该合成方法利用铜和氧气作为氧化体系,无需额外添加其他氧化剂,副产物只有氮气,是一个比较绿色的合成磺酰胺类化合物的方法.     

三组分反应合成多官能团化α-氰基噻吩的简便方法

本文报道了一种利用多组分反应合成α-氰基噻吩的新方法. 在碱存在条件下, β-二羰基化合物、二硫化碳和溴乙腈经过连续的多步反应, “一锅”合成多官能团化的α-氰基噻吩. 该方法简洁, 条件温和, 产率高.     

α-烷氧酰胺亚甲基膦酸酯合成方法的研究

α-烷氧酰胺亚甲基膦酸酯由于亚甲基结构的特殊性使得其合成方法很有限,针对该问题研究了这一类型化合物的合成方法学.以乙酸乙酯作为溶剂,在氢氧化锂碱性条件下,α-芳磺酰亚甲基氨基甲酸酯与磷酸二酯反应能以良好至中等的产率顺利地合成常见方法难以合成的α-烷氧酰胺亚甲基膦酸酯.该方法操作简便,条件温和,并可应用于克级规模反应.     

Convenient synthesis of fluoroalkyl α- and β-aminophosphonates

Addition of both alkyl phosphites and phosphonate α-carbanions to N-substituted aldimines derived from fluoroalkyl aldehydes presents a convenient method for synthesis of fluoroalkyl α- and β-aminophosphonates in good yield (55-86%) under mild conditions.     

4-Acetoxy-2,2-dimethylbutanoate: a useful carbohydrate protecting group for the selective formation of β-(1→3)-d-glucans

The use of 4-acetoxy-2,2-dimethylbutanoyl protecting group for the C2-hydroxyl allows the selective formation of β-glycosides without producing α-glycosides. This very bulky protecting group can be removed under mild conditions.     

Efficient and mild benzoin condensation reaction catalyzed by simple 1-N-alkyl-3-methylimidazolium salts

The benzoin reaction, catalyzed by simple 1-N-alkyl-3-methylimidazolium salt-based ionic liquid via carbene intermediate, to give the α-hydroxyl ketone proceeds in CH₂Cl₂ under mild conditions.     

芳香环状聚膦酸酯齐聚物的基质辅助激光解吸电离飞行时间质谱分析

用基质辅助激光解吸电离飞行时间质谱方法对一系列芳香环状聚膦酸酯低聚物进行了结构分析。比较了不同基质及阳离子剂对芳香环状聚膦酸酯分析结果的影响。1,8,9-蒽三酚基质仅对含有羰基基团聚膦酸酯环状齐聚物分析有效,而视黄酸基质则对所有聚膦酸酯环状剂聚物有效,是这类新型芳香环状齐聚物的适宜基质。环状聚膦酸酯齐聚物的阳离子齐分析表明,氯化锂是这种环状齐聚物的适宜的阳离子添加剂。     

Nucleoside 5′-C-phosphonates: reactivity of the α-hydroxyphosphonate moiety

We found that various dialkyl phosphites, dialkyl trimethylsilyl phosphites, and tris-trimethylsilyl phosphite reacted smoothly with nucleoside 5′-aldehydes to afford epimeric nucleoside 5′-C-phosphonates in high yields. A number of these compounds in both the 2′-deoxyribo and ribo series were prepared. In the case of 2′-deoxythymidine-5′-aldehyde, a thorough study was made on the influence of the 3′-hydroxyl protecting group, type of phosphite, base, and solvent, on the yield and epimeric ratio of the resulting 5′-hydroxyphosphonates. Partial stereoselectivity in favour of either R or S epimers was observed. An attempt to transform the α-hydroxyl of the phosphonate moiety into a halo or azido moiety was not successful. Only intramolecular substitution reaction of the mesyloxy group for an alkoxy residue of the 2-hydroxyethyl ester took place in a low yield.     

SYNTHESIS, CHARACTERIZATION AND RING-OPENING POLYMERIZATION OF CYCLIC (ARYLENE PHOSPHONATE) OLIGOMERS

INTRODUCTIONThe use of cyclic oligomers as macrocyclic precursors for the preparation of high performance polymers byring-opening polymerization (ROP) has sparked much interest in recent years. It could produce a revolutionarychange in the preparation of advanced composite materials, and is of great importance in the polymerizationprocess yielding polymers such as the reinforced reactive injection model (RRIM) and the resin transfer model(RTM) etc. Within the last 10 years, the synthes…     

Cu(II)-catalyzed enantioselective 1,3-dipolar cycloaddition of nitrones with α, β-unsaturated acyl phosphonates

A highly enantioselective 1, 3-dipolar cycloaddition of nitrone with α, β-unsaturated acyl phosphonate was developed for the first time by using a chiral indane-bis(oxazoline)-copper(II) complex. The reaction proceeded smoothly under mild conditions to provide isoxazolidines with multi-stereocenters in good yields with high to excellent diastereo- (>20:1 dr) and enantioselectivities (up to 99% ee). The resulting products were readily converted to multi-functional isoxazolidines or γ-amino alcohol compounds.     

Diastereoselective additions of allylmetal reagents to free and protected syn-α,β-dihydroxyketones enable efficient synthetic routes to methyl trioxacarcinoside A

Two routes to the 2,6-dideoxysugar methyl trioxacarcinoside A are described. Each was enabled by an apparent α-chelation-controlled addition of an allylmetal reagent to a ketone substrate containing a free α-hydroxyl group and a β-hydroxyl substituent, either free or protected as the corresponding di-tert-butylmethyl silyl ether. Both routes provide practical access to gram quantities of trioxacarcinose A in a form suitable for glycosidic coupling reactions.     

α-Amino acetals containing a phosphonate or phosphine oxide group. Synthesis and reactions with resorcinols

New α-amino acetals containing a phosphonate or phosphine oxide group were synthesized by the Kabachnik-Fields reaction in the ternary system amino acetal-paraformaldehyde-dialkyl phosphonate (or dialkylphosphine oxide). Condensation of dialkyl (2,2-dimethoxyethylamino)methylphosphonates with resorcinol and its derivatives in ethanol in the presence of hydrochloric acid, apart from the corresponding 2,2-bis(polyhydroxyphenyl) ethylammonium salts, gave 2,5-bis(polyhydroxyphenyl)-1,4-bis[(dialkoxyphosphoryl)methyl]-piperazines. Dialkyl[(2,2-dimethoxyethylamino)methyl]phosphine oxides (Alk = C₈H₁₇, C₁₀H₂₁) did not react with resorcinol derivatives under similar conditions, and analogous ammonium salts were obtained by heating the reactants in boiling trifluoroacetic acid.