费托(FT)合成及相关反应的研究进展(英文)

按催化剂分类介绍了改性ＦＴ合成及与其相关反应的近期研究成果。即通过调制催化剂组成和反应条件,由合成气直接合成其他有价值的化工原料如醇、烯烃、芳香烃和石蜡等。分子筛,如ＡＩ－ＭＣＭ－４１和ＺＳＭ－５／磷铝分子筛等在ＦＴ及其相关反应中扮演着越来越重要的角色,但由于金属作为反应活性中心,所以金属催化剂如Ｆｅ,Ｃｏ、Ｐｄ、Ｒｈ和Ｎｉ,双金属如Ｆｅ－Ｉｒ和Ｐｔ－Ｍｏ仍然是人们研究的重点。另外,一些新的反应方法和新的材料也被采用,如超临界方法及超微粒催化剂等。     

甲醇气相氧化羰基化合成碳酸二甲酯的研究Ⅲ. 催化剂的失活再生

碳酸二甲酯 (ＤＭＣ)是一种对环境友好的绿色化学品 ,其洁净合成工艺的开发 ,已引起国内外研究者的广泛重视。真田等人[1 ] 对ＰｄＣｌ2 存在下ＣＯ和亚硝酸甲酯反应合成ＤＭＣ过程所用催化剂的失活原因和再生方法进行了研究 ,认为ＰｄＣｌ2 中的Ｃｌ被还原消除生成氯甲酸甲酯导致催化剂失活 ,并发现氯甲酸甲酯在ＤＭＣ合成中可使Ｐｄ催化剂再生和提高寿命。ＤＯＷ公司[2 ] 开发的气相氧化羰基化法催化剂ＣｕＣｌ2-ＫＣｌ ＡＣ易失活 ,该催化剂运行 50～ 1 0 0ｈ后需进行再生。再生时 ,于 1 2 0℃条件下通入 1 0 %ＨＣｌ Ｎ2 混合物 ,再生后…     

合成低碳醇超细Mo-Co-K催化剂的TPD研究

近年来 ,Ｍｏ基催化剂由于其独特的耐硫性而在各种合成低碳醇催化剂体系中倍受青睐。许多研究表明 ,以Ｃｏ作为Ｍｏ基催化剂的第二组分可明显改善其催化合成低碳醇的反应性能[1～ 4] 。一般认为 ,Ｋ是这类催化剂通用的促进剂[1,3 ,5,6] 。我们曾经报道[7] ,还原态超细Ｍｏ Ｃｏ Ｋ催化剂具有优良的合成低碳醇性能。同时 ,催化剂的Ｃｏ Ｍｏ比对其合成低碳醇性能具有显著的影响。为了解这种影响的原因 ,本文运用ＴＰＤ技术对此类催化剂进行了研究。催化剂经还原后 ,在催化剂表面即形成了不同的吸附中心[8] 。了解这些不同的吸附中心 ,对于研…     

Li-La/NaZSM-5催化剂的表征及其酯交换性能的研究

用氧化物对ＮａＺＳＭ－５分子筛进行改性来调节其表面酸碱性，已越来越受到人们重视，本文报道用Ｌｉ２Ｏ、Ｌａ２Ｏ３双组份对ＮａＺＳＭ－５进行改性，并将改性分子筛用作甲醇和碳酸乙烯酯（简称ＢＣ）反应制碳酸二甲酯（简称ＤＭＣ）体系的催化剂。文献报道用作此反应...     

含钛MCM-48分子筛上二十碳醇氧化制二十碳酸

采用水热合成法制备含钛ＭＣＭ－４８型中孔分子筛系列催化剂，用ＩＲ和ＸＲＤ等技术对催化剂进行了表征，对α－二十碳醇氧化制α－二十碳酸反应进行了研究，对目的反应的催化性能进行了评价，并确定出反应的最佳温度和反应时间，结果表明，添加适量的Ｔｉ可提高α－二十碳酸的收率。用ＩＲ技术对目的产物进行跟踪分析，所得结果与化学检测结果一致，将反应产物的收率与分子筛催化剂的Ｌ酸进行了关联。     

CuZSM-5分子筛上苯酚羟化制苯二酚

在Ｎａ２Ｏ－ＳｉＯ２－ＣｕＯ－Ｈ２Ｏ体系中以１５％ＴＰＡＢｒ－８５％ＨＭＤＡ为模板剂合成了ＣｕＺＳＭ－５分子筛，并用ＸＲＤ，ＩＲ及ＳＥＭ等方法进行了表征，考察了ＣｕＺＳＭ－５分子筛催化苯酚与过氧化氢的羟化活性，研究了催化剂用量、反应温度、反应时间及ｎ（ＰｈＯＨ）／ｎ（Ｈ２Ｏ２）等对羟化活性的影响．     

复合催化剂中H-ZSM-5酸性对合成气制二甲醚的影响

对合成气制二甲醚（ Ｄ Ｍ Ｅ）复合催化剂中脱水组分 Ｈ Ｚ Ｓ Ｍ ５ 分子筛进行水热处理及 Ｎ Ｈ３ Ｔ Ｐ Ｄ、 Ｃ Ｏ２ Ｔ Ｐ Ｄ 表征． 研究结果表明, 在 Ｈ Ｚ Ｓ Ｍ ５ 分子筛脱水组分上具有两种酸性中心,高温 Ｎ Ｈ３ 的脱附峰代表强酸中心, 低温 Ｎ Ｈ３ 的脱附峰代表弱酸中心． 同时, 亦有两种不同强度的碱中心． 随 Ｈ Ｚ Ｓ Ｍ ５ 水热处理温度的提高, 总酸量及强酸中心数量逐渐降低, 碱性中心数目随 Ｈ Ｚ Ｓ Ｍ ５ 水热处理温度的提高略有增加, Ｄ Ｍ Ｅ的选择性随之提高． Ｄ Ｍ Ｅ 主要是在 Ｈ Ｚ Ｓ Ｍ５ 分子筛的弱酸中心上生成． 对 Ｈ Ｚ Ｓ Ｍ５ 于 ６００ ℃处理后与铜基催化剂混合制得的复合催化剂, 对其反应性能考察后发现, 当 Ｈ２／ Ｃ Ｏ≈２ 时, ４～６ Ｍ Ｐａ、２ ０００～３ ０００ ｈ－ １、２６０ ℃为最适宜反应条件． 此时, Ｃ Ｏ 的转化率≥ ９０％ , 对 Ｄ Ｍ Ｅ 和甲醇的选择性为９６％ , Ｄ Ｍ Ｅ 在所有有机产物中的选择性≥ ８０％ , Ｄ Ｍ Ｅ的含量≥ ２０％ ． 提高反应压力, Ｃ Ｏ 的转化率及 Ｄ Ｍ Ｅ 在产物中的含量有较大提高, 但对 Ｄ Ｍ Ｅ的选择性影响不大．     

MCM—48介孔分子筛的合成研究

利用水热法合成了ＭＣＭ－４８介孔分子筛,通过ＩＲ,ＴＧ－ＤＴＡ,ＸＲＤ,ＸＲＤ,ＴＥＭ,Ｎ２吸附等方法对产物进行了表征,并系统地研究了晶化温度、晶化时间、凝胶组成等对合成ＭＣＭ－４８介孔分子筛的影响。     

具有独特结构的分子筛

具有独特结构的分子筛ＭｏｂｉｌＲ＆Ｄ公司最近合成了一种从未有过的、结构独特的分子筛，它的两组独立的孔系由，所谓的１０－环隙连为一体。这种罕见的分子筛叫做ＭＣＭ－２２，在石油化学领域内用作催化剂的前景看好。其组成化学式为Ｈ０．０３３Ｎａ０．０４３（Ａｌ...     

苯酚和草酸二甲酯在不同分子筛催化下的酯交换反应

研究了以TS－1、H－ZSM－5、Hβ和H－丝光沸石等不同分子筛为催化剂，苯酚和草酸二甲酯酯交换合成草酸二苯酯反应。通过对催化剂进行吸附吡啶的红外光谱和NH3－TPD表征，考察了不同分子筛催化剂的酸性和酸强度对草酸二苯酯合成反应的影响，确定了催化剂上的弱酸中心是催化苯酚和草酸二甲酯酯交换合成草酸二苯酯反应的活性位，且催化剂的酸性中心越多，酸量越大，催化活性越好。催化剂上的强酸中心促进了副产物苯甲醚的生成。     

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.     

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.     

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.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

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.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

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.     

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.