固态有机反应新进展

总结了一些典型的固态有机反应。由于固态反应的特性，多数固态有机反应表现出较溶液中更高的反应效率和更好的选择性，在某些情况下，利用光活性主体与反应物形成包结物，可实现对映选择性的不对称固态合成。     

含噻吩基的三硅烷在辐照下的反应

通过类似的格氏反应合成了2-苯基-2-呋喃基六甲基三硅烷和2-苯基-2-噻吩基六甲基三硅烷.前者在2,3-二甲基-1,3-丁二烯存在时的光解导致正常的硅烯-烯烃加成和硅烯C-H插入反应.而噻吩基三硅烷在甲醇一环乙烷体系中被光解,产生自由基反应,我们怀疑噻吩中的硫原子对硅烷自由基有强烈的稳定作用.通过对典型的自由基反应产品的鉴定以及它的用自由基猝灭剂的猝灭产品的电子自旋共振谱也支持了这一结果.     

有机锑化合物在交叉偶联反应中的应用研究进展

近年来,有机锑化合物在交叉偶联反应中的应用引起了人们的广泛关注。本文主要对有机锑化合物在交叉偶联反应中的应用作了综述,重点介绍了其在Suzuki交叉偶联反应、Heck偶联反应以及Sonogashira偶联反应中的应用,并展望了其未来的发展方向。     

固态有机合成反应进展

以绿色合成为主题，综述了近期固相有机合成研究方面的一些新进展和典型反 应类型。由于固相反应的特征，多数固相有机反应表现出较溶液中更高的反应效率 和更好的选择性，并讨论了固态反应中的分子运动及其固态反应的因素。     

卤代苯催化加氢脱除卤素反应的研究

采用可溶性有机高分子负载钯络合物作催化剂,在无机碱（NaOH)存在下于20－65℃的有机溶液中进行常压加氢脱卤反应。研究了脱卤反应的温度、溶剂量、碱量、压力对反应的影响。结果表明明：负载钯络合催化内化效率高、反应体系简单、无副反应,是一种很好的卤代苯加氢脱方法,在有机工业和环保中有广阔的应用前景。     

Passerini多组分反应研究进展

多组分反应操作简便、原子经济性高,是一类重要的有机反应。经典Passerini反应是以异腈、醛酮、羧酸为原料一步合成α-酰氧基酰胺的多组分反应,其产物作为重要的有机中间体,可以进一步合成许多重要的药物、天然产物和功能材料等复杂有机分子,具有广泛的应用价值。本文从反应底物、串联反应及相关应用的角度阐述近5年来Passerini多组分反应研究的新进展。     

水相体系中的碳碳成键反应

水是质子供体,又是质子受体,又因具有较大的疏脂性质,故在许多有机反应中水不宜作为溶剂使用。在某些反应体系中,微量水的存在就会使产率大为降低甚至完全不反应。因此无水要求常见于有机反应的实验过程。然而,近年来发现某些过去常在无水溶剂中进行的有机反应其实也可以在水溶剂体系中进行,且也能得到非常好的结果。下面举几个例子。     

反应薄层在有机实验中的应用

反应薄层就是将反应物点在薄层板上,选择合适的反应条件进行板上反应之后,再选择展开剂展开,根据展开结果进行反应情况的研究. Miuer等人首先在50年代开创并发展了直接在薄层板上实现有机反应的工作.以后国内外学者又陆续在薄层上进行氧化、还原、水解、卤代、酯化、衍生物的制备等研究.本文只是介绍几个把反应薄层用于基础有机化学实验的实例.     

光催化有机物偶联/芳构化放氢反应研究进展

光催化氧化还原反应具有绿色、高效、安全等优势,已经在有机化学中得到广泛关注.介绍了基于光催化的偶联/芳构化放氢反应,通过使用光催化剂/催化剂的双催化体系,可用于光催化有机碳-碳和碳-杂原子成键反应,且反应中氢气是唯一的副产物.强调了有机光氧化还原体系的构建与催化机理.     

有机反应的竞争性

有机反应的竞争性胡秀贞（南京师范大学化学系，２１００２４）竞争反应是有机化学中一个相当普遍的反应，所以我们研究有机反应机理时，必须具有有关这个反应的热力学和动力学的基本知识。大家知道热力学研究的一个重要内容是反应的起始状态和终止状态的能量变化，而动力...     

Kinetic Evidence for Reactive Intermediates

Spectroscopic methods have recently been developed that allow the direct detection of reactive intermediates under favorable circumstances. The most general and reliable method, however, is still the indirect one, which makes use of the priciple of kinetic competition; this method is based on the freedom of the intermediate to choose between several reaction possibilities. The following discussion is addressed less to the specialist in reaction mechanisms than to the outsider who wishes to obtain some idea of the value and limitations of the kinetic method.     

Structure du méthyl-3 phénylamino-4 phényl-5 triazole-1,2,4

The crystal structure or 3-methyl-4-phenylamino-5-phenyl-1,2,4-triazole has been determined by X-ray diffraction. It allows one to choose between the two reaction mechanisms which can be taken into account for the reaction of hydrazine upon N-acylated hydrezonates.     

Catalytic studies of the gaseous exchange Reaction H2/HDO using Platinum on Charcoal

In the gaseous exchange reaction H₂/HDO the catalyst (Pt/Charcoal) of concentration 0.4 gm Pt per 100 ml catalyst proved to be highly efficient. Its preparation is simple but precaution is needed to choose, optimum conditions in activating the charcoal prior to impregnation, the right grain size to reduce channelling, the proper reduction process and an efficient purification system to remove poisons. The regeneration of the catalyst is described. The kinetics and mechanism of this reaction are discussed.     

Photoaktivierung des homogenen hydrierungskatalysators IrCl(CO)L2, als funktion des liganden l und der substrate

The possibility of good photoactivation depends on the ligand L in IrCl(CO)L₂ and on the substrate S. No relationship was found between the photoactivation of the catalyst, the ligand L and the substrate. It is a matter of experiment to choose optimum reaction conditions.     

Pentanary cross-diffusion in water-in-oil microemulsions loaded with two components of the Belousov-Zhabotinsky reaction

We measure cross-diffusion coefficients in a five-component system, an aerosol OT (AOT) water-in-oil microemulsion loaded with two constituents of the Belousov-Zhabotinsky (BZ) reaction (H(2) O/AOT/BZ1/BZ2/octane). The species BZ1 is either NaBr, an inhibitor of the BZ reaction, or ferroin, a catalyst for the reaction. As species BZ2, we choose Br(2) , an intermediate in the reaction. The cross-diffusion coefficients between BZ1 and BZ2 are found to be negative, which can be understood in terms of complexation between these species. Using a four-variable model for the BZ reaction, we find that the cross-diffusion coefficients measured here can lead to a noticeable shift in the onset of Turing instability in the BZ-AOT system.     

利用比例脉冲控制B-Z反应中混沌的变量选择

自二十世纪七十年代以来 ,混沌现象的研究成为非线性科学中的前沿课题。混沌在其无规律的表面下隐藏着惊人的“秩序”,但在许多情况下 ,混沌属于不利因素 ,因此近年来混沌控制又成为倍受关注的热点 ,出现了各种各样的混沌控制方法。这些混沌控制方法可以分为两大类 ,一类以Ott,Grebogi,Yorke提出的 OGY方法 [1]为代表 ,通过对系统参数实行控制达到混沌控制的目的。另一类以比例脉冲控制法[2 ,3] 为代表 ,由控制系统变量利用系统自身非线性特征实现系统自身反馈达到混沌控制目的。这两类方法各自分别能有效地控制不同特点的混沌系统 ,而比…     

遥爪型液体聚合物及其多相共聚物——Ⅷ.端羧基乙烯基四氢呋喃-环氧丙烷液体聚合物与甲基丙烯酸缩水甘油酯的交联

本文研究了端羧基乙烯基四氢呋喃-环氧丙烷液体共聚物(TVC-PTP)与甲基丙烯酸缩水甘油酯(GMA)的反应。观察了组成比,催化剂等对反应产物力学性能的影响。用红外光谱跟踪了这一反应过程,观察了乙烯基和环氧基的消失速度。用平衡溶胀法测定了交联聚合物单位体积内有效交联链的数目和交联点间平均分子量,观察了它们对交联聚合物力学性能的影响。     

Purine N-oxides—XL The 3-acyloxypurine 8-substitution reaction: Scope: Syntheses of 8-substituted xanthines and guanines

The 3-acyloxypurine 8-substitution reaction is a substitution-elimination reaction involving attack at C-8 by inorganic or organic nucleophiles and departure of an acyloxy group from N-3. It has been studied with 3-acetoxyxanthine, 3-hydroxyguanine and a number of related derivatives and is the method of choice for the preparation of many 8-substituted xanthines or guanines. It proceeds extremely rapidly in neutral aqueous solutions at room temperature. With water alone an 8-hydroxypurine results, and water always competes to some degree with other nucleophiles. The reaction can be carried out in dipolar aprotic solvents, in which it is also possible to prepare the acyloxy derivative in situ and to choose more effective leaving groups such as mesyloxy or tosyloxy. The reaction has been demonstrated with chloride, bromide, nitrite, and azide ions; with the thioether of methionine; a variety of pyridine derivatives, and with primary and secondary alcohols. This reaction is apparently restricted to 3-acyloxypurines which are also substituted at position-2. The behaviour of 3-acetoxy-1-methylxanthine is similar to that of 3-acetoxyxanthine, but 3-acetoxy-7-methylxanthine fails to undergo the reaction.     

Sorbitol and gluconic acid production using permeabilized Zymomonas mobilis cells confined by hollow-fiber membranes

Immobilization of Zymomonas mobilis by different methods was investigated. Experiments were performed order to choose the most appropriate support for the immobilization of the cells. The most advantageous option was to use permeabilized cells in the bore of microporous hollow fibers. Whereas the reaction rate was about 33 g of gluconate/ (g of protein·h) using hollow fibers, which is comparable to that observed by using free cells, the calcium alginate immobilized cells presented a reaction rate of 4 g of gluconate/ (g of protein·h). These results can be explained by the mass transfer resistance effect, which, indeed, was much lower in the case of hollow-fiber membranes than in the alginate gel beads. A loss of enzymatic activity during the reaction was observed in all experiments, which was attributed to the lactone produced as an intermediate of the reaction.     

MFC逆转化CO2合成甲醇研究

微生物燃料电池(MFC)反应器是利用附着在阳极上的产氢微生物,在吸收烟气CO2的同时将CO2逆转化合成高附加值的生物合成燃料的装置。试验选用从牛粪中分离筛选出的梭状芽孢菌(Clostridium.sp)作为合成生物燃料的合成菌,将MFC反应装置接入电化学工作站进行CV测试,当发生还原反应时,在-0.5 V时出现还原峰,利用直流稳压电源恒电压电解,检测到合成的生物燃料为甲醇。在24 h时甲醇的积累量达到最大3.13 mmol/L;当CO2气体比例为15%时甲醇积累量最大,为2.98 mmol/L。在细菌接种量为1 mL时,甲醇积累量达到最大,为2.76 mmol/L。,最适条件下的CO2转化率为7.5%。