β－Mo2N0．78的合成及其对噻吩加氢脱硫反应的催化性能

 以N2－H2混合气为反应气，与三氧化钼进行多段程序升温反应制得了氮化钼．考察了反应气组成和氮化温度等条件对氮化钼结构组成的影响．结果表明，在n（N2）／n（H2）＝0．25～1，θ＝650～750℃的条件下，生成的氮化钼结构组成为β－Mo2N0．78．其生成机理与γ－Mo2N有类似之处．β－Mo2N0．78催化噻吩加氢脱硫反应的结果表明，β－Mo2N0．78催化剂对该反应有较高的催化活性，在360℃下，其活性比硫化钼催化剂高一倍左右．     

铁/活性炭催化剂的氮化及其碳化行为

用原位穆斯堡尔谱考察了不同担载量的Ｆｅ／ＡＣ催化剂的氮化以及随后的碳化行为。Ｆｅ／ＡＣ催化剂经５００℃Ｈ预还原后，于３５０℃流动态氨气中氮化５小时可生成ε－氮化铁，其穆斯堡尔谱呈双峰（δ～０．４２ｍｍ／ｓ，△～０．３２ｍｍ／ｓ）。再在合成气（２Ｈ２／ＣＯ）中进行碳化处理，ε－氮化铁中的氮原子可逐渐被碳原子取代而转化为氮碳化铁和碳化铁，但铁的担载量越高，这种取代越困难。８％Ｆｅ／ＡＣ催化剂在２５０℃     

两相体系中钌膦配合物催化4—苯基—3—丁烯—2—酮加氢反应的研究

研究了水和有机物组成的两相催化体系中,由ＲｕＣｌ３－ＴＰＰＴＳ（ＴＰＰＴＳ：Ｐ（ｍ－Ｃ６Ｈ４ＳＯ３Ｎａ）３）原位反应生成的催化活性物种对４－苯基－３－丁烯－２－酮（又名苄叉丙酮）的催化加氢反应．考察了钌浓度（１．０×１０－３～６．０×１０－３ｍｏｌ／Ｌ）、氢压（１．０～６．０ＭＰａ）、反应温度（３０～７０℃）、配体浓度（１．２～７．２×１０－２ｍｏｌ／Ｌ）、阳离子表面活性剂（ＣＴＡＢ：十六烷基三甲基溴化铵）及反应时间等对加氢反应活性和选择性的影响,并与以配合物ＲｕＣｌ２（ＴＰＰＴＳ）３为催化剂前体生成的催化活性物种对加氢反应的活性及选择性进行了比较．结果表明,分别由配合物ＲｕＣｌ２（ＴＰＰＴＳ）３及ＲｕＣｌ３－ＴＰＰＴＳ原位反应生成的催化活性物种,都只催化４－苯基－３－丁烯－２－酮的Ｃ＝Ｃ键选择加氢．由配合物ＲｕＣｌ２（ＴＰＰＴＳ）３形成的催化体系的加氢活性及选择性均优于ＲｕＣｌ３－ＴＰＰＴＳ原位反应生成的催化活性物种．阳离子表面活性剂的加入,使加氢反应活性下降,选择性略有提高     

芳胺常压气相N—烷基化反应研究

在固定床催化反应器中常压下研究了芳胺和醇的气相法Ｎ－烷基化反应。考察了γ－Ａｌ２Ｏ３系列催化剂的反应性能，筛选出了两种适用于苯胺Ｎ－甲基化反应且性能较好的催化剂。反应条件为：在甲醇和苯胺的摩尔比为３：１时，反应温度为２８０℃，液时空速为０．３ｈ＾－１的条件下，苯胺转化率为９９％，生成Ｎ，Ｎ－二甲基苯胺（ＤＭＡ）的选择性为９２％。研究了甲醇和芳环上不同位置取代的甲基苯胺的反应规律，其转化率顺序：苯胺     

芳胺常压气相N－烷基化反应研究

在固定床催化反应器中常压下研究了芳胺和醇的气相法Ｎ－烷基化反应。考察了γ－Ａｌ２Ｏ３系列催化剂的反应性能，筛选出了两种适用于苯胺Ｎ－甲基化反应且性能较好的催化剂。反应条件为：在甲醇和苯胺的摩尔比为３１时，反应温度为２８０℃，液时空速为０．３ｈ－１的条件下，苯胺转化率为９９％，生成Ｎ，Ｎ－二甲基苯胺（ＤＭＡ）的选择性为９２％。研究了甲醇和芳环上不同位置取代的甲基苯胺的反应规律，其转化率顺序：苯胺≈对一甲苯胺≈间－甲苯胺＞邻－甲苯胺。从Ｃ１到Ｃ４不同结构的醇和苯胺反应的规律研究，证明随醇中碳原子数目的增加，醇的反应活性降低，正构醇和苯胺反应和异构醇与苯胺反应随温度升高的变化趋势相反。     

二苯并噻吩在CoMoNx催化剂上的加氢脱硫

以ＭｏＯ３及沉淀法制得的ＣｏＭｏ氧化物为前驱体,在Ｎ２－Ｈ２混合气中用程序升温反应制得一系列氮化（钴）钼催化剂;用二苯并噻吩加氢脱硫为模型反应,考察了催化剂的催化性能。结果表明：⑴二苯并噻吩在氮化钼催化剂上的加氢脱硫有两条反应途径,即噻吩环直接氢解加氢脱硫;苯环先加氢,然后噻吩环氢解脱硫。⑵氮化钼有高的活性和选择Ｃ—Ｓ键断裂生成联苯的选择性,Ｃｏ的加入明显提高了氮化钼的催化活性。⑶不同预处理条件对     

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     

两相催化体系中α，β－不饱和醛的选择性加氢反应研究Ⅰ．水溶性钌－膦配合物催化肉桂醛的加氢性能

本文研究了两种水溶性钌－膦配合物ＲｕＣｌ_２（ＴＰＰＴＳ）_３和Ｒｕｃｌ_２（ＣＯ）_２（ＴＰＰＴＳ）_２［ＴＰＰＴＳ为：Ｐ（ｍ－Ｃ_６Ｈ_４ＳＯ_３Ｎａ）_３］的合成，在水相和有机相组成的两相催化体系中，考察了它们衍生出的活性物种和以ＲｕＣｌ３－ＴＰＰＴＳ原位合成的活性物种对肉桂醛的选择加氢性能，并对反应温度（２０—８０℃），氢压（２—６ＭＰａ），催化剂浓度（１．１２×１０~（－３）～４．５０×１０~（－３）ｍｏｌ／Ｌ），配体ＴＰＰＴＳ浓度（９．０×１０~（－３）～５．４×１０~（－２）ｍｏｌ／Ｌ），表面活性剂浓度和反应时间的变化对选择加氢反应的影响进行了详细研究。实验结果表明，ＲｕＣｌ_３－ＴＰＰＴＳ原位合成配合物的催化加氢活性最高，而在金属Ｒｕ上羰基的配位将使加氢活性降低，表面活性剂ＣＴＡＢ是有效的促进剂，它的加入可大大提高加氢活性，选择适当的ＣＴＡＢ浓度，在反应结束后水相与有机相分层迅速，有利于Ｒｕ催化剂的分离，在所考察的反应条件下，肉桂醛选择加氢生成肉桂醇的转化率大于８０％，选择性达９６％以上。     

丙醛均相催化加氢制丙醇的研究

系统地研究了在４．０ＭＰａ氢压下，反应温度、催化剂浓度、溶剂等对丙醛均相加氢制正丙醇反应的影响，得出最佳反应条件为：氢压４．０ＭＰａ、温度８０℃，ＲｕＣｌ３·３Ｈ２Ｏ为催化剂前体，用量９８ｍｇ（０．３５ｍｍｏｌ），ＰＰｈ３为３９３ｍｇ（１．５ｍｍｏｌ），Ｒｕ／Ｐ摩尔比为１／４，ＤＭＦ为溶剂．在此条件下，丙醛转化率和正丙醇选择性可分别达９９％和９５％以上．求出了不同反应温度下的反应速度常数．以ＲｕＣｌ３－ＰＰｈ３为催化剂体系，丙醛加氢的活化能为７７．６２ｋＪ／ｍｏｌ     

双重负载钯催化剂用于硝基化合物的催化加氢

将可溶的聚乙烯吡咯烷酮负载的钯催化剂进一步负载到γ－Ａｌ２Ｏ３上，得到双重负载的钯催化剂。在少量碱的存在下，这种双重负载的钯催化剂在常温常压下对硝基苯的催化加氢表现出非常高的活性。γ－Ａｌ２Ｏ３负载的聚乙烯吡咯烷酮钯催化剂［ＰＶＰ－Ｐｄ／Ａｌ２Ｏ３（ｍｅｔｈｏｄＢ）］对硝基苯和ｐ－甲基硝基苯加氢的ＴＯＦｍａｘ（ｍａｘｉｍｕｍｔｕｒｎｏｖｅｒｆｒｅｑｕｅｎｃｙ，ｎ（Ｈ２）／（ｎ（Ｐｄ）．ｔ）），分别     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

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.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.