NiMoNx/γ-Al2O3催化剂的制备及加氢脱氮性能

采用程度升温氮化（ＴＰＮ）的方法制备了ＮｉＭｏＮｘ／γ－Ａｌ２Ｏ３催化剂，考察了它对吡啶加氢脱氮（ＨＤＮ）反应的催化活性。结果表明，ＮｉＭｏＮｘ／γ－Ａｌ２Ｏ３催化剂的活性远远高于ＮｉＭｏＳｘ／γ－Ａｌ２Ｏ３催化剂和工业硫化态催化剂。对于ＮｉＭｏＺｘ／γ－Ａｌ２Ｏ３催化剂，助剂Ｎｉ的作用与硫化物体系中的Ｎｉ不同，它不仅是活化氢中心，同时也是脱氮中之心一，ＮｉＭｏＮｘ／γ－Ａｌ２Ｏ３催化剂的ＨＤＮ活     

TiO2调变对MoO3／γ—Al2O3和CoO—MoO3／γ—Al2O3催化性能的影响

采用气相流动吸附法制备ＴｉＯ２／γ－Ａｌ２Ｏ３复合载体，用浸渍法其担载一定量的ＭｏＯ３或ＣｏＯ－ＭｏＯ３。用ＸＲＤ、ＬＲＳ和ＴＰＲ等技术，考察了Ｍｏ或Ｃｏ－Ｍｏ催化剂的表面结构和还原性能，并有和中压固定床反应装置测定催化剂的噻吩加氢脱硫和环己烯加氢的活性。     

炭担载的Mo和CoMo加氢脱硫催化剂

用仲钼酸铵和酸钴水溶液浸渍方法将ＭｏＯ３和ＣｏＯ担载在少在性炭担体上，制成Ｍｏ／Ｃ和ＣｏＭｏ／Ｃ催化剂。运用ＤＴＡ，ＸＰＳ，ＦＴ－ＬＲＳ等手段考察了ＭｎＯ３在活性炭担体表面的分散状态及Ｈ２还原能力随ＭｏＯ３含量的变化，并在中压固定床反应装置上测定了催化剂的噻吩加氢脱硫和环己烯加氢反应活性。     

MoO_3（MOVS）系列催化剂上喹啉的加氯脱氮

将金属氧化物蒸汽合成法（ＭｅｔａｌＯｘｉｄｅＶａｐｏｕｒＳｙｎｔｈｅｓｉｓＭＯＶＳ）制各的Ｎｉ－Ｍｏ（ＭＯＶＳ）－Ｐ／Ａｌ２Ｏ３催化剂用于喹啉的加氧脱氮（ＨＤＮ）。结果表明，与常规方法制备的同类催化剂相比，ＭＯＶＳ催化剂具有较高的ＨＤＮ活性，主要表现在Ｃ－Ｎ键断裂和苯环加氢催化活性的提高。在负载高含量ＭｏＯ３方面，ＭＯＶＳ方法还有待进一步完善。文章还讨论了制备条件（酸度，载体种类等）对催化活性的影响。     

CoMo／Al_2O_3和CoMo／TiO_2－Al_2O_3加氢脱硫催化剂的研

研究了ＣｏＭｏ／Ａｌ２Ｏ３和ＣｏＭｏ／ＴｉＯ２－Ａｌ２Ｏ３催化剂的加氢脱硫性能，并用ＬＲＳ，ＸＲＤ和ＴＰＳ等方法表征其表面相结构和硫化行为．结果表明，以ＴｉＯ２－Ａｌ２Ｏ３为担体的Ｍｏ和ＣｏＭｏ催化剂的活性均比相应的Ａｌ２Ｏ３为担体的高；少量Ｃｏ，Ｎｉ助剂的引入可显著提高ＭｏＯ３在担体上的分散度和改进催化剂的活性；Ｃｏ助剂还有降低Ｍｏ物种硫化温度的作用．     

Mo－Fe／SiO_2催化剂中钼流失动力学和流失机理的研究

作为甲醇氧化制甲醛、甲醇氨氧化制ＨＣＮ反应的催化剂，其活性组分钼的流失是导致催化剂失活的主要原因。本文结合程序升温脱附（ＴＰＤ）及Ｘ－光衍射（ＸＲＤ）等测试手段，对Ｍｏ－Ｆｅ／ＳｉＯ_２催化剂及工业实际用多元复合钼催化剂中钼的流失动力学和机理进行了研究。在ＨＣＮ合成过程中，水能引起活性组分钼的流失，而水又是反应产物。对工业用多元复合钼催化剂的流失情况进行了动力学考察，实验发现，催化剂中的钼是较难流失的，ＸＲＤ测试结果表明，Ｍｏ－Ｆｅ／ＳｉＯ_２催化剂中的钼是以Ｆｅ_２（ＭｏＯ_４）_３晶体形式存在的，而反应后催化剂中Ｍｏ为ＭｏＯ_３晶体状态。与其它催化剂比较，ＭｏＯ_３／ＳｉＯ_２催化剂中的钼难流失，而较Ｂｉ－Ｍｏ／ＳｉＯ_２催化剂中的钼易流失。其中工业用催化剂是最为稳定的。根据实验结果，结合我们以前的工作，证明Ｍｏ－Ｆｅ／ＳｉＯ_２催化剂中，由于钼组分和铁组分的相互作用，使得Ｍｏ－Ｆｅ／ＳｉＯ_２中的Ｍｏ的流失难于单组分的ＭｏＯ_３／ＳｉＯ_２催化剂，此外钼流失过程中ＭｏＯ_２（ＯＨ）_２与催化剂中铁组分反应生成钼酸盐的倾向也是Ｍｏ难于流失的原因之一。而Ｍｏ－Ｆｅ／ＳｉＯ_２和Ｍｏ－Ｂｉ／ＳｉＯ_２催化剂中钼流失速度的差异     

在MoO3／SiO2及其添加体系上甲烷部分氧化制甲醛的研究

在常压下，以Ｏ２作氧化剂，评价了不同ＭｏＯ３／ＳｉＯ２（２─１５Ｍｏｗｔ％）催化剂对甲烷选择氧化为甲醛的反应性能，发现ＳｉＯ２上担载的活性组分有一个最佳值，对应最佳催化活性．分别考察了添加Ｖ、Ｆｅ、Ｎｉ、Ｃｒ、Ｃｕ氧化物对ＭｏＯ３／ＳｉＯ２催化剂甲烷选择氧化制甲醛的活性和选择性的调变作用．ＭｏＯ３／ＳｉＯ２添加体系使甲烷的转化率都有所提高，但甲醛选择性有不同程度的下降，其中比较好的是ＭｏＯ３·Ｖ２Ｏ５／ＳｉＯ２催化剂，并研究了不同Ｍｏ／（Ｍｏ＋Ｖ）（原子比）对反应活性和选择性的影响，发现Ｖ２Ｏ５添加量有最佳值．采用ＴＰＲ、ＸＲＤ、ＣＯ２─ＴＰＤ等技术对催化剂进行表征并关联反应性能进行了讨论．     

MoNiP/Al2O3加氢脱氮催化剂的研究:金属分散状态对催化剂活性的影响

采用ＰＡＳＣ Ａ，ＸＰＳ，ＳＴＥＭ和微型反应色谱等技术，研究了一系列ＭｏＮｉＰ／Ａｌ２Ｏ３催化剂表面活性组分的分散状态及其对催化剂ＨＤＮ反应活性的影响。     

Mo/SiO2及V改性的Mo/SiO2催化剂的微孔特征及其对甲烷部分氧化合成甲醛反应的影响

在常压下评价Ｍｏ／ＳｉＯ２催化剂的制备条件对反应性能的，利用Ｎ２的吸附等温线计算了Ｍｏ－Ｖ／ＳｉＯ２催化剂的比表面积和孔径分布，进而讨论了不同的Ｖ加入量对Ｍｏ／ＳｉＯ２催化剂的微孔特征及其催化性能的影响，找到了适宜的Ｖ／Ｍｏ质量比及使甲醛收率最高的最佳孔径，通过ＸＲＤ和ＴＥＭ的测试分析讨论了制备条件对微观状态的影响和Ｖ与Ｍｏ之间的相互作用。     

MoO＿3／（TiO＿2－SiO＿2）催化剂的表面分散状态及催化性能的研究

用气相流动吸附法（ｇｒａｆｔｉｎｇ）制备复合载体，用浸渍法（ｉｍｐｒｅｇｎａｔｉｏｎ）制备ＭｏＯ３／（ＴｉＯ２－ＳｉＯ２）催化剂．应用ＬＲＳ和ＴＰＲ技术研究ＭｏＯ３在复合载体ＴｉＯ２－ＳｉＯ２表面的分散状态，发现ＴｉＯ２在ＳｉＯ２表面的分散可增强ＭｏＯ３与载体之间的相互作用，提高ＭｏＯ３在载体表面的分散阈值．催化剂的活性评价在固定床中压反应装置中进行，以６９％（ｗｔ）环己烷、２０％（ｗｔ）的环己烯、１０％（ｗｔ）的苯、１％（ｗｔ）的噻吩混合液为反应液，以噻吩、环己烯和苯的转化率作为催化剂的ＨＤＳ、ＨＹＤ、ＢＨＤ活性指标．结果表明，经ＴｉＯ２调变后，其ＨＤＳ、ＨＹＤ、ＢＨＤ活性都较原来高，对于不同ＭｏＯ３含量的ＭｏＯ３／（ＴｉＯ２－ＳｉＯ２），ＨＤＳ、ＨＹＤ催化性能测试发现，当ＭｏＯ３含量低于分散阈值时，其ＨＤＳ、ＨＹＤ活性随ＭｏＯ３含量线性上升，但在高于分散阈值后，几乎保持不变．该催化剂对苯几乎没有加氢活性，显示出很高的环己烯加氢选择性．通过分散阈值与其ＨＤＳ、ＨＹＤ活性的关系可知，分散阈值可作为优化加氢精制催化剂配比的一个重要参数，具有较强的实际意义     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.