制备高碳醇用Cu－Fe系催化剂的活性相

用共沉淀法制备了Ｃｕ－Ｆｅ系催化剂，它是由脂肪酸甲酯加氢制备高碳醇的新催化体系．催化剂经焙烧后的物相为ＣｕＯ，γ－Ｆｅ２Ｏ３和ＭｇＯ，形成了活性相的结构前驱．在反应条件下，ＣｕＯ首先被还原为金属态的Ｃｕ０，然后γ－Ｆｅ２Ｏ３被还原为Ｆｅ３Ｏ４；Ｃｕ０和Ｆｅ３Ｏ４共同参与催化该反应．本文用ＸＲＤ，ＴＧ－ＤＴＡ和Ｍｏｓｓｂａｕｅｒ谱等手段，结合催化剂的活性测定，确定了催化剂的活性相为Ｃｕ０和Ｆｅ３Ｏ４；ＭｇＯ可改变催化剂的电子结构和几何构型，起到重要的助催化作用     

沉淀法制备Fe－Ti系合成醇催化剂

在压力６ＭＰａ，空速５０００ｈ－１下，采用微反－色谱－微处理机联合装置，对沉淀法制备的Ｆｅ－Ｔｉ系合成低碳醇催化剂的活性和选择性进行了测定．在配料组成相同的情况下，并流法和反加法制成的催化剂活性较高，３５０℃时催化剂上的最高醇收率为０．５５７ｇ／（ｍｌ·ｈ），Ｃ２醇（碳数大于或等于２的醇）的最高含量为３８．３％．实验结果表明，并流法制得的氧化态催化剂具有非晶态结构和较大的表面积．提高焙烧温度，反加法所制氧化态催化剂的衍射峰强度减弱，表明铁、钛组分间有某种相互作用．正加法所制催化剂的氧化态主要物相为α－Ｆｅ２Ｏ３，叠加扫描后发现有少量Ｆｅ２Ｔｉ３Ｏ９晶相．程序升温还原的结果表明，催化剂的还原经历了脱去外表水和铁组分还原等过程，但低温下催化剂不能充分还原．采用峰形鉴别法和逐步逼进法得到了主还原阶段的动力学参数．不同催化剂活性和选择性的差异，归因于不同制备方法使得沉淀的铁组分和浸渍的钛组分的均匀度和分散度不同，以及Ｆｅ－Ｔｉ组分的相互作用不同．     

多乙苯脱氢制多乙烯苯氧化铁催化剂的研究助剂钾,铈对催化性能的影响

研制了适合多乙苯脱氢制多乙烯苯的Ｆｅ－Ｋ－Ｃｅ复合型脱氢催化剂．助剂钾以钾霞石（ＫＡｌＳｉＯ４）方式引入，既克服了钾的大量流失，又保留了钾碱的抗积炭性能，使催化剂活性稳定．另一助剂ＣｅＯ２的加入对催化剂中的各组分起到了一定的分散作用，使催化剂晶粒度变小，并且提高了活性组分Ｆｅ２Ｏ３的还原温度，因而可增强催化剂的抗还原能力．     

制备高碳醇稀土改性Cu-Fe催化剂

在Ｃｕ－Ｆｅ系催经剂中添加稀土,利用稀土改性提高Ｃｕ－Ｆｅ系催化剂的活性,或直接利用氮氢混合气还原脂肪酸酯制备碳脂肪醇。用纯氢气作气源,添加１％的Ｓｍ２Ｏ３,高碳醇收率可提高约３％。用氮氢混合气作气源,不含稀土的Ｃｕ－Ｆｅ系催化剂活性大幅度下降,添加Ｙ、ＮＤ等可阻止其活性下降甚至提高其活性,与不含稀土的Ｃｕ－Ｆｅ系催化剂相比,添加１％的Ｎｄ２Ｏ３或１％的Ｙ２Ｏ３可分别提高碳醇收率２９％和３３％。     

多乙苯脱氢制多乙烯苯氧化铁催化剂的研究:助剂钾，铈对催化性能的影响

研制了适合多乙苯脱氢制多乙烯苯的Ｆｅ－Ｋ－Ｃｅ复合型氢催化剂，助剂钾以外霞石（ＫＡｌＳｉＯ４）方式引入，既克服了钾的大量流失，又保留了钾的抗积炭性能，使催化剂活性稳定，另一助剂ＣｅＯ２的加入对催化剂中的各组分起到了一定的分散作用，使催化剂晶粒度变小，并且提高了活性组分Ｆｅ２Ｏ３的还原温度，因而可增强催化剂的抗还原能力。     

Fe_2O_3／ZrO_2催化剂上一氧化碳加氢反应制低碳烯烃 Ⅱ．预处理条件对催化剂结构及性能的影响

用ＴＰＲ，Ｍｏｓｓｂａｕｅｒ谱法，ＸＰＳ，ＸＲＤ及反应评价等手段研究了Ｆｅ２Ｏ３／ＺｒＯ２催化剂的还原行为、铁物种状态和ＣＯ加氢反应性能．结果表明，预处理条件明显影响Ｆｅ２Ｏ３／ＺｒＯ２催化剂表面铁原子的数量、铁锆间的相互作用、催化剂的物相变化以及ＣＯ加氢反应的催化性能．以Ｆｅ２Ｏ３／ＺｒＯ２经氢氟混合气程序升温至７５３Ｋ还原生成的Ｆｅ－Ｚｒ－Ｏ物种为前身，在合成气中进一步还原得到的铁锆催化剂，具有较好的Ｆ－Ｔ反应合成低碳烯烃的选择性．     

丁二烯聚合反应用FeCl3-Al(i-Bu)3-Phen催化剂体系相态的研究

通过Ｔｙｎｄａｌｌ效应，电镜观察和超过滤实验，发现ＦｅＣｌ３－Ａｌ（ｉ－Ｂｕ）３－Ｐｈｅｎ，催化剂在溶有丁二烯的加氢汽油介质中为胶体分散系，活性中心位于胶体催化剂的胶粒表面，催化剂各组分间的配比影响有胶粒形态，以较佳配所得到的催化剂颗粒较小，分布均匀，催化活性高。     

预处理条件对用于CO_2加氢的超细CuO－ZnO－SiO_2催化剂性能的影响

采用ＸＲＤ、ＢＥＴ、ＴＰＲ手段，研究了焙烧和还原温度对超细ＣｕＯ－ＺｎＯ－ＳｉＯ２催化剂的性质及其ＣＯ２加氢反应催化活性的影响．胶体在５７３－７７３Ｋ范围内焙烧生成ＣｕＯ、Ｃｕ２Ｏ、ＺｎＯ晶相，随着焙烧温度继续升高，ＣｕＯ和ＺｎＯ晶粒逐渐变大，但催化剂的比表面积和孔容变化很小．在９７３Ｋ焙烧后出现Ｚｎ２ＳｉＯ４晶相，使催化剂比表积和孔容变小，导致催化剂活性降低．焙烧温度对催化剂活性的影响大于对ＣＯ２加氢产物分布的影响．在５４８－６４８Ｋ范围内，催化剂还原温度对其催化活性影响不大．７０３Ｋ高温还原后，可能由于Ｃｕ０晶粒的出现，使得催化剂的活性下降．ＴＰＲ研究结果进一步表明，焙烧温度影响ＣｕＯ同ＺｎＯ、ＳｉＯ２之间的相互作用和催化剂的还原行为．     

CuO／CeO2和CuO／Al2O3催化剂的催化性能

本文以ＣＯ氧化为模式反应考察了ＣｅＯ２和Ａｌ２Ｏ３负载氧化铜催化剂的氧化活性，运用ＸＲＤ和ＴＰＲ技术研究了催化剂的还原性能和物相结构，结果表明：载体性质对负载ＣｕＯ催化剂的ＣＯ氧化活性有很大影响，ＣｕＯ／ＣｅＯ２催化剂活性明显高于ＣｕＯ／Ａｌ２Ｏ３催化剂．催化剂的还原特性随载体不同而不同．同时发现，热处理对催化剂铜物种的存在形式，晶粒大小、还原特性及其催化活性有明显影响，ＣｕＯ／Ａｌ２Ｏ３催化剂活性下降的主要因素是生成了活性较低的ＣｕＡｌ２Ｏ４相，而ＣｕＯ／ＣｅＯ２催化剂活性下降是由于ＣｕＯ和ＣｅＯ２发生烧结，晶粒变大     

沉淀介质对合成醇Cu-Co-Fe系催化剂的影响

分别以水和乙醇为沉淀介质，按不同方法制备了低碳醇合成用Ｃｕ－Ｃｏ－Ｆｅ系催化剂．以乙醇为沉淀介质时，有利于提高生成低碳醇的活性和选择性，产物中正构醇含量增加，且不服从Ｓｃｈｕｌｚ－Ｆｌｏｒｙ方程分布方式．乙醇的存在，使沉淀体系中的杂质ＮａＮＯ３不易洗脱，催化剂还原温度提高；高的ＮａＮＯ３含量对进一步提高催化剂的活性和选择性不利．吸附实验结果表明，乙醇的预处理可提高催化剂对ＣＯ的不可逆吸附能力，提高还原温度则会使催化剂对ＣＯ的不可逆吸附能力减弱．提高催化活性和选择性的方法是用乙醇修饰催化剂，并降低其中ＮａＮＯ３的含量     

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.     

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.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.     

Copper-catalyzed multicomponent reactions of 2-iodoanilines,benzylamines, and elemental sulfur toward 2-arylbenzothiazoles

A relatively cheap copper salt-catalyzed, three-component approach providing 2-arylbenzothiazoles in good to excellent yields from readily available 2-iodoanilines, benzylamines, and sulfur powder is reported. This methodology allows preparation of various classes of 2-arylbenzothiazoles and provides a general, reliable approach.