用全氟磺酸离子交换树脂多相催化合成不对称醚

醚类化合物是有机化学工业和医药工业上常用的溶剂。又如甲基叔丁基醚沸点低、辛烷值高可作无铅汽油,特别是高级无铅航空汽油的添加剂。Cottle、Wolff等人曾用硫酸、磷酸、有机金属化合物和聚苯乙烯磺酸型离子交换树脂作催化剂,通过醇和烯烃的加成反应合成了对称的和不对称的醚。本文采用酸性比聚苯乙烯磺酸强,但对反应容器无任何腐蚀,操作简便,无三废的全氟磺酸离子交换树脂(以后简称全氟磺酸)作催化剂,合成了甲基叔丁基醚;乙基叔丁基醚;异丙基叔丁基醚和仲丁基叔丁基醚。     

全氟磺酸树脂/SiO2催化合成邻苯二甲酸二辛酯

全氟磺酸树脂/SiO2催化合成邻苯二甲酸二辛酯;固体酸;全氟磺酸离子交换膜;全氟磺酸树脂/SiO2复合物催化剂;邻苯二甲酸二辛酯     

阳离子交换树脂的有机催化进展

综述了聚苯乙烯型磺酸树脂、全氟磺酸树脂Nafion及崭新的Nafion／siO_2复 合催化剂在有机合成中应用的最新进展．     

以强酸性阳离子交换树脂为催化剂合成14-氧杂二环[10,3,0]十五碳烯-2

以三种类型的强酸性阳离子交换树脂(聚苯乙烯磺酸树脂、酚醛磺酸树脂和全氟磺酸树脂)为催化剂进行环十二碳-烯的普林斯反应,合成了14-氧杂二环[10,3,0]十五碳烯-2.考察了该三种树脂的催化性能,并与苯磺酸和对甲苯磺酸的催化性能作了比较.考察了孔径、粒度及反应条件(温度、时间、催化剂用量等)对聚苯乙烯磺酸树脂催化性能的影响.实验结果表明:全氟磺酸树脂和交联大孔聚苯乙烯磺酸树脂(交联度10％,孔径3.9×10²Å,比表面积20m²/g)具有良好的催化性能.     

全氟磺酸钯树脂催化的芳基卤与烯烃或炔烃的反应

全氟离子交换树酯[Perfluoririnted ion-exchange resin(PFIER)]由于其化学稳定性极好,因此用它作为高分子载体具有独特的优越性。全氟磺酸树脂作为强酸性催化剂,在有机合成中的应用已有广泛的研究。近年来,用高分子载体催化剂代替传统的小分子催化剂进行反应,由于后处理和催化剂回收方便而受到重视。但是,用含金属或金属阳离子的离子交换树脂作为金属催化剂参与的反应却研究得很少。     

新形态全氟磺酸树脂催化剂研究进展

全氟磺酸树脂是绿色固体酸催化剂，对许多反应有较好的催化活性和选择性。但由于全氟磺酸树脂比表面较低，埋没在氟碳基体中的酸性中心不易被反应物所接近，质量比活性低。本文对近年来新形态全氟磺酸树脂，如多孔、负载化、纳米复合物及其改性的全氟磺酸树脂的催化作用进行了综述，文献结果表明全氟磺酸树脂纳米复合物对很多有机合成反应具有很高的催化活性。     

引入离子基团改善聚苯乙烯与热致液晶聚合物的相容性 Ⅱ用FTIR研究分子间特殊相互作用

向聚苯乙烯（ＰＳ）中引入磺酸基团可以有效地改善ＰＳ与一种热致液晶聚合物（ＬＣＰ）之间的相容性．用溶液共混的方法制备了ＰＳ和磺化聚苯乙烯（ＨＳＰＳ）与ＬＣＰ的共混物．用ＦＴＩＲ以及红外光谱的合成技术对ＬＣＰ共混体系进行了表征．共混物中组分聚合物特征吸收的位置和谱图的形状表明在ＬＣＰ与ＰＳ分子间没有相互作用发生，而在ＬＣＰ与ＨＳＰＳ分子间则存在较强的相互作用．谱图差减技术确认了ＬＣＰ分子中ＣＯ与ＣＯ基团和ＨＳＰＳ中的磺酸基团参与了相互作用，使得这些基团的特征吸收发生了偏移．     

SiO2载负回收全氟磺酸树脂催化乙酸丁酯合成

SiO2载负回收全氟磺酸树脂催化乙酸丁酯合成;固体酸;全氟磺酸树脂/二氧化硅复合物催化剂     

固体超强酸研究的最新进展

简要介绍了近年来固体超强酸的发展。目前研究较多的固体超强酸有负载硫酸超强酸、Ｃｓ２．５盐、ＡｌＣｌ３／ＰＳ－ＤＶＢ磺酸树脂体系和全氟磺酸树脂（Ｎａｆｉｏｎ－Ｈ－Ｈ ＰＥＩＥＰ）四种。文章主要阐述了这几种固体超强酸的制备方法及它们的性质比较。     

全氟4-甲基-3,6-二氧杂-△~7-辛基磺酰氟及有关化合物的合成

全氟4-甲基-3,6-二氧杂-△~7-辛基磺酰氟是合成全氟磺酸离子交换树脂的共聚单体,此单体在文献中除有关专利简单报导外,尚未见其合成和结构鉴定等方面的详细资料。我们在合成全氟磺酸离子交换树脂的过程中,对它以及其有关化合物的合成进行了研究。     

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.     

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.     

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.     

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.