可循环利用硅胶吸附三氯化铈-碘化钠催化1,3-二酮的 烷基化无溶剂反应

在无溶剂条件下, 硅胶吸附的水合三氯化铈-碘化钠(CeCl3?7H2O-NaI)可以作为路易斯(Lewis)酸有效催化活泼亚甲基化合物和烯丙醇的直接烷基化反应, 得到较高产率的烷基化产物(62%～90%). 该催化剂经过简单处理至少可以循环利用四次, 第四次循环后产率达到78%.     

硫酸亚铈催化的芳香化合物与苄基醇、烯丙醇类化合物以及苄基氯的傅-克烷基化反应研究

硫酸亚铈作为一种便宜的和有效的催化剂催化芳香化合物与苄基醇、烯丙醇类化合物和苄基氯的傅-克烷基化反应. 在1～10 mol%的硫酸亚铈存在下, 芳香化合物分别与苄基醇、烯丙醇类化合物和苄基氯能够顺利有效地进行傅-克烷基化反应. 此外, 催化剂能回收, 再次使用三次也没有明显地失去催化活性.     

CuBr/1,8-二氮杂双环[5.4.0]十一碳-7-烯催化苄醇的选择性空气氧化反应（英文）

发展了一种新型、实用性的以溴化亚铜为催化剂,以1,8-二氮杂双环[5.4.0]十一碳-7-烯(DBU)为添加剂,在空气条件下进行氧气氧化苄醇的催化体系.各种一级或二级苄醇及烯丙醇可以以高的产率及选择性转换为相应的醛和酮.该过程为无溶剂反应,同时不需要使用四甲基哌啶氧化物(TEMPO)类助氧化剂.     

无溶剂下位阻控制的Biginelli反应

在NaHSO4作催化剂, 无溶剂下将水杨醛、活泼亚甲基化合物和尿素或硫脲进行Biginelli 反应, 高收率地合成了一系列monastrol类物质. 产物的结构通过IR, 1H NMR, 13C NMR光谱数据和单晶解析表征和确定. 对于不同活泼亚甲基化合物参与的反应, 形成了4-(2-羟基苯基)嘧啶衍生物2和氧桥嘧啶衍生物3两类物质, 活泼亚甲基化合物分子中醇酯基的结构是决定两种嘧啶衍生物结构的主要因素. 对于以前报道的Biginelli产物4-(2-羟基苯基)嘧啶衍生物2a和氧桥嘧啶衍生物3e的形成也进行了讨论.     

树脂固载的β—酮砜的烷基化反应

Samuelsson等由季铵盐、碱和β-酮砜化合物制得相应的β-酮砜阴离子季铵盐,可直接用于烷基化反应。此法较经典方法虽有条件温和,产率较高的优点,但分离麻烦,季铵盐用量大且不能回收.聚合物负载的季铵盐作为相转移催化剂和反应底物的载体,已用于含活泼亚甲基化合物的烷基化反应.本文用离子交换法制得了大孔季铵盐离子固载的β-酮砜阴离子试剂,探索了这种试剂的烷基化反应条件,制得了一系列β-酮砜化合物的衍生物。     

盐酸洛美利嗪的合成新工艺研究

本论文研究了一条哌嗪类脑血管扩张药物洛美利嗪的合成新路线,以双(4-氟苯基)甲基酮(2)为原料经还原,氯代,再与哌嗪反应得1-[双(4-氟苯基)甲基]哌嗪(5),此化合物与2,3,4-三甲氧基苄醇经"一锅法"还原氨化实现醇与氨基的直接氮烷基化从而制得洛美利嗪。该方法是新型"一锅法"还原氨化方法在此类药物上的首次应用,实现了以更加温和、经济的条件合成此类药物的目的。     

过渡金属催化1,3-二羰基化合物不对称烯丙基烷基化反应的研究进展

1,3-二羰基化合物的不对称烯丙基烷基化反应是构筑手性中心的重要方法.综述了过渡金属催化1,3-二羰基化合物不对称烯丙基烷基化反应的进展.按照烯丙基化试剂的不同,主要讨论了以烯丙基酯类、烯丙醇、烯丙基卤化物、烯烃、联烯作为烯丙基化试剂或其他烯丙基化方法合成手性α-烯丙基取代的1,3-二羰基化合物.     

金属有机钛化合物对脂肪酸与芳香醇酯化反应的催化作用

酯的合成方法很多,常用的方法是有机酸和醇的直接酯化,催化剂一般有H_2SO_4,分子筛等.但对于羧酸和苄醇的直接酯化,其产率往往不高,这是因为苄基有着较大的空间阻碍.为提高产率,一般是采用酰卤醇解法或羧酸钠盐与氯苄反应,或通过季胺盐热分解法制备羧酸苄酯.本文用己酸和苄醇在二氯二茂钛催化剂作用下直接酯化,其酯产率与文献中的正丁酸苄酯相近.以有机钛化合物为催化剂的酯化,具有催化剂用量少,装置简单,操作方便,且后处理简便,产率较高等优点.     

用于催化氧气氧化苄醇到醛的新型且简单的催化体系（溴化铜/TEMPO/哌啶）

构建了一个可用于催化氧气氧化苄醇类醇到醛的新型催化体系(溴化铜/四甲基哌啶氧化物/哌啶).该体系以乙腈为溶剂,可以在50℃下高活性和选择性地催化氧气将含不同取代基的苄醇氧化为相应的醛.然而,该体系对于仲醇、脂肪族伯醇以及烯丙醇类型醇的氧化没有催化活性.     

酸性沸石分子筛催化Knoevenagel缩合反应

 在高硅／铝比的酸性沸石分子筛HY上实现了Knoevenagel缩合反应．Bronsted酸和Lewis酸均可催化Knoevenagel缩合反应．考察了羰基化合物和活泼亚甲基化合物的反应活性顺序．结果表明，羰基化合物的羰基极化程度越高，反应越容易进行；不同于碱催化时的Knoevenagel缩合反应，活泼亚甲基化合物的活泼氢的酸性并不是影响其反应活性的重要因素．     

Enantioselective allylic substitution of cinnamyl esters catalyzed by iridium-chiral aryl phosphite complex: conspicuous change in the mechanistic spectrum by a countercation and solvent

Iridium-catalyzed asymmetric allylic alkylation of monoaryl substrates 4-6 with chiral phosphites 1-3 has been investigated. Although branched isomers were formed with high regioselectivities, the enantioselectivities of these products were remarkably influenced by solvents, countercations, and additives (ZnCl(2) and LiCl).     

Highly efficient alkylation to ketones and aldimines with Grignard reagents catalyzed by zinc(II) chloride

A highly efficient alkylation to ketones and aldimines with Grignard reagents in the presence of catalytic trialkylzinc(II) ate complexes derived from ZnCl2 (10 mol %) in situ was developed. This simple Zn(II)-catalyzed alkylation could minimize the well-known but serious problems with the use of only Grignard reagents, which leads to reduction and aldol side products, and the yield of desired alkylation products could be improved.     

Synthesis and Characterization of Novel Layered Lithium Sodium Silicate （Silinaite） and the Mesoporous Materials from Silinaite

Novel layered silinaite has been synthesized using an aqueous mixture of water glass, LiOH and NaOH under hydrothermal crystallization. Subsequently transformation of silinaite into mesoporous materials (SDM) was achieved at mild condition using cetyltrimethylammonium bromide as structure-directing agents. The resulting samples were characterized by XRD, SEM, FTIR nitrogen adsorption-desorption isotherms and catalytic performance in bulky molecular involved reaction. The results revealed that synthesized mesoporous materials derived from the silinaite exhibited an ordered hexagonal crystal structure with average pore diameter 2.7 nm and BET surface area 817m2/g. The SDM-supported ZnCl2 catalyst, prepared by impregnation-evaporation method, retained the mesoporous structure and showed high selectivity in alkylation of benzene with benzyl chloride.     

Ammonia, cyclohexane, nitrogen and water adsorption capacities of an activated carbon impregnated with increasing amounts of ZnCl(2), and designed to chemisorb gaseous NH(3) from an air stream

The adsorption capacity of ZnCl(2)-impregnated activated carbon (AC) for NH(3) is reported in terms of stoichiometric ratio of reaction (NH(3) per ZnCl(2)). This ratio depends on the testing conditions used. Compared to the ratio obtained under dry conditions, the ratio is higher under humid conditions or increased NH(3) concentrations. The linear increase of the NH(3) capacity with increasing loading of ZnCl(2) breaks down at about 3.5 mmol ZnCl(2)/g AC. This behavior is explained in terms of preferential adsorption of a monolayer of salt followed by aggregation of the impregnant once a monolayer is completed. The effect of increasing the loading of ZnCl(2) on the capacity for gases for which the impregnants are not intended, namely cyclohexane, nitrogen, and water vapor, is also discussed. A break in the linear relationship between water capacity and impregnant loading at about 3.5 mmol ZnCl(2) seems to correspond to a full monolayer coverage of ZnCl(2) on AC. The monolayer of ZnCl(2) is shown to reduce the uptake of water into AC, while the ZnCl(2) aggregates are shown to be hydrophilic.     

微波辐射促进ZnCl2与Y分子筛固相反应的研究

ZnCl2/Y catalysts prepared by solid-state reaction of anhydrous ZnCl2 and Y zeolites under microwave irradiation were characterized by XRD, IR and AAS. ZnCl2 was intercalated in Y zeolites and dispersed on the surface of Y zeolite, part of ZnCl2 dispersed could result in solid-state ion exchange with Y. The amount of dispersion and solid-state ion exchange were related to ZnCl2 loading and the surface acid property of the zeolite. When ZnCl2 loading was 37.5% (mass fraction) in NaY zeolite, ZnCl2 was still completely dispersed on the surf are of zeolite and the degree of solid- state ion exchang was 84%. The appearance of new band at 890 cm-l in the framework IR spectra of ZnCl2/NaY sample was due to the dispersed ZnCl2 coordinating strongly with oxygen of NaY surface. With the increasing of the number of arid centers and the acid strength of the surface of Y zeolite the amount of solid-state ion exchange decreased.     

微波辐射促进ZnCl_2与Y分子筛固相反应的研究

采用XRD、IR和原子吸收光谱等手段对微波固相法制备的ZnCl2／Y催化剂进行了表征·微波辐射促进了ZnCl2在分子筛表面分散和固态离子交换，分散的ZnCl2可与分子筛表面氧原子发生较强的配住键合作用．当ZnCl2的负载量达到37．5％时，ZnCl2仍可完全分散于NaY分子筛表面，此时的固态离子交换度为84％．随着分子筛表面酸菌和区强度的增加，ZnCl2与分子筛的固态离子交换量减少．     

Structural characterization of zinc(II) chloride in aqueous solution and in the protic ionic liquid ethyl ammonium nitrate by x-ray absorption spectroscopy

Extended x-ray absorption fine structure (EXAFS) spectroscopy has been used to investigate the species and structures existing in a series of ZnCl(2)-H(2)O-NaCl solutions with different chloride/zinc ratios and in a solution of ZnCl(2) in the protic ionic liquid ethyl ammonium nitrate (EAN). The average coordination numbers and distances of zinc species were determined from the analysis of the EXAFS data. In aqueous solution the number of chloride ions tightly bounded to Zn(2+) is significantly related to the chloride/zinc ratio, and no inner complex formation between Zn(2+) and Cl(-) ions has been detected for low ZnCl(2) concentration (0.1 and 0.2 M). Conversely, in the same concentration range (0.13 M) the ZnCl(2) species do not dissociate in EAN and the Zn(2+) first coordination shell has two chloride ions and is completed by two oxygen atoms of the nitrate anion. The results of this investigation show that notwithstanding the existence of similar characteristics between EAN and water, the solvation properties of the two solvents are markedly different.     

分子筛表面酸性对微波固相法制备ZnCl2/Y催化剂的影响

 采用XRD和原子吸收光谱法研究了微波作用下分子筛表面酸性对ZnCl2与Y分子筛固态相互作用的影响．结果表明，微波辐射可显著促进ZnCl2在分子筛表面分散，其分散阈值与分子筛表面酸性有关．随着分子筛表面酸量和酸强度增加，ZnCl2在分子筛表面的最大分散量减少，分散的ZnCl2与Y分子筛的固态离子交换量也减少；NaY型分子筛比HY分子筛更容易发生固态离子交换反应．考察了微波固相法制备的ZnCl2／HY催化剂在苯甲醚与乙酰氯酰化反应中的催化性能．结果表明，在分子筛表面分散的ZnCl2具有更高的催化活性及对甲氧基苯乙酮选择性．     

Direct amino acid-catalyzed cascade biomimetic reductive alkylations: application to the asymmetric synthesis of Hajos-Parrish ketone analogues

A direct amino acid-catalyzed chemo- and enantioselective process for the double cascade synthesis of highly substituted 2-alkyl-cyclopentane-1,3-diones, 2-alkyl-3-methoxy-cyclopent-2-enones and Hajos-Parrish (H-P) ketone analogs is presented via reductive alkylation chemistry. For the first time, we have developed a single-step alkylation of cyclopentane-1,3-dione with aldehydes/ketones and a Hantzsch ester through an organocatalytic reductive alkylation strategy. A direct combination of amino acid-catalyzed cascade olefination-hydrogenation and cascade Robinson annulations of cyclopentane-1,3-dione, aldehydes/ketones, a Hantzsch ester and methyl vinyl ketone furnished the highly functionalized H-P ketone analogues in good to high yields and with excellent enantioselectivities. Many of the reductive alkylation products have shown direct applications in pharmaceutical chemistry.     

ZnCl2改性离子交换树脂的制备及其催化乙醇和乙酸酯化反应性能

 采用离子交换法制备了 ZnCl2 改性的阳离子交换树脂催化剂, 考察了 ZnCl2 浓度、离子交换时间和溶剂等对催化剂催化乙酸和乙醇微波酯化反应性能的影响. 结果表明, 以去离子水为溶剂, 以 0.15%ZnCl2 溶液进行离子交换 30 h, 所得催化剂的性能较好. 采用酸碱滴定法、紫外-可见光谱、傅里叶变换红外光谱、扫描电镜和 N2 吸附脱附等手段对催化剂进行了表征. 结果表明, 改性后的催化剂 H+交换量约为原来的 1.5 倍, 表面酸强度增加; 树脂骨架结构变化不大; 紫外吸收峰发生蓝移, 吸收强度减小; 比表面积略有减小; 催化剂在含水体系中表现出较高的催化活性, 且重复使用性能大大提高.