Mechanistic Studies of the Solvolyses of Carbamoyl Chlorides and Related Reactions

Carbamoyl chlorides are important intermediates, both in the research laboratory and in industrial scale syntheses. The most studied and used are the disubstituted derivatives, incorporating either aryl or alkyl groups (Ar₂NCOCl or R₂NCOCl). Sometimes, the groups are tied back to give a ring and piperidino- and morpholino-derivatives are commonly encountered. Some studies have been made with two different groups attached. Solvolyses tend to occur at the carbonyl carbon, with replacement of the chloride ion. Studies of both rate and products are reviewed and the solvolysis reactions are usually S_N1, although addition of an amine leads to a superimposable bimolecular component. Many of the studies under solvolytic conditions include the application of the extended Grunwald–Winstein equation. The monosubstituted derivatives (ArNHCOCl or RNHCOCl) are less studied. They are readily prepared by the addition of HCl to an isocyanate. In acetonitrile, they decompose to set up and reach equilibrium with the isocyanate (ArNCO or RNCO) and HCl. Considering that the structurally related formyl chloride (HOCOCl) is highly unstable (with formation of HCl + CO₂), the unsubstituted carbamoyl chloride (H₂NCOCl) is remarkably stable. Recommended synthetic procedures require it to survive reaction temperatures in the 300–400 °C range. There has been very little study of its reactions.     

直接Z-Scheme异质结Al-PMOFs/CdZnS光催化剂的制备及其光催化苯甲胺氧化性能

摘要：采用水热法合成了具有立方柱状结构的卟啉基金属有机框架化合物(Al-PMOFs),然后通过共沉淀法将CdZnS纳米颗粒沉积在Al-PMOFs棱柱上,得到了界面接触良好的异质结Al-PMOFs/CdZnS纳米杂化材料。将催化剂应用于可见光催化苯甲胺氧化偶联反应中,结果表明,Al-PMOFs/CdZnS纳米复合材料具有较好的光催化反应活性和稳定性。室温下当溶剂为N,N-二甲基甲酰胺(DMF)时,经可见光照射7 h后,苯甲胺可以发生氧化偶联反应生成N-苄基-1-苯基甲亚胺(BPMI),苯甲胺的转化率可达97%,BPMI 的选择性超过99%,复合材料的光催化活性较相同条件下单一的CdZnS和Al-PMOFs提高了2倍。Al-PMOFs/CdZnS光催化性能的提高主要归因于Al-PMOFs与CdZnS之间形成了直接Z-scheme异质结,该异质结能够促进Al-PMOFs和CdZnS界面上的电荷传输,抑制Al-PMOFs/CdZnS杂化材料表面光生载流子的复合。通过自由基捕获实验等提出了适合该体系的直接Z-scheme光催化反应机理以及电荷转移路径。     

2-氯-5-三氟甲基吡啶的合成

以氯化苄为原料,经过5步反应合成2-氯-5-三氟甲基吡啶.实验考察了反应条件对合成反应的影响,产品总收率达到37.4%.     

异硫氰酸镱苄胺配合物的合成及其热分解非等温动力学研究

本文叙述了异硫氰酸镱苄胺配合物Yb(NCS)_3·4C_6H_5CH_2NH_2的合成方法。通过对该配合物进行热分解非等温动力学研究,推断了该配合物的热分解反应机理及动力学补偿效应表达式。     

Pressure synthesis of dibenzylamine from benzylamine and benzyl alcohol

The synthesis of dibenzylamine from benzylamine and benzyl alcohol in the presence of a phosphoric acid catalyst has been carried out under pressure. Very high pressure has no beneficial effect on the synthesis of dibenzylamine. Under optimum conditions (473K, 3.10×10⁶Nm^?2; residence period 2h; benzylamine to benzyl alcohol mol. ratio, 1:2 and benzylamine to catalyst mol. ratio, 1:0.2174), the conversion of benzylamine to dibenzylamine was 88.50%.     

Photo- and electroluminescent properties of bithiophene disubstituted 1,3,4-thiadiazoles and their application as active components in organic light emitting diodes

Photo- and electroluminescence of five bithiophene disubstituted 1,3,4-thiadiazoles, constituting a new class of solution processable materials for organic opto-electronics, were studied. It was found that the introduction of alkyl solubilizing substituents bathochromically shifted the photo- and electroluminescence bands. The most pronounced effect was observed for the substitution at the C_α position which changed the emitting light color from bluish to green. All five derivatives were tested in host/guest type organic light emitting diodes (OLEDs) with either poly(N-vinylcarbazole) (PVK) or poly(N-vinylcarbazole) + 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PVK + PBD) matrices. The latter matrix turned out especially well suited for these guest molecules yielding devices of varying color coordinates. The best luminance (750 cd/m²) was measured for 2,5-bis(5′-octyl-2,2′-bithiophene-5-yl)-1,3,4-thiadiazole with the luminous efficiency exceeding 0.4 cd/A.     

N,N-二乙酸乙酯苄胺的合成及其表征

以苄胺和溴代乙酸乙酯为原料，干苯为溶剂，三乙胺为质子吸收剂，合成了Ｎ，Ｎ－二乙酸乙酯苄胺，产率为８０％。介绍了该物质的分离纯化方法，并用＾１ＨＮＭＲ及质谱对其进行了结构表征。     

离子对反相高效液相色谱同时测定对氟苄胺、邻氟苄胺、间氟苄胺及苄胺含量

目的:用离子对反相高效液相色谱法测定对氟苄胺、邻氟苄胺、间氟苄胺及苄胺含量。方法:在C8色谱柱上,以离子对试剂缓冲液(用磷酸调节pH至2.5)+乙腈(80+20,体积比)为流动相,分离对氟苄胺、邻氟苄胺、间氟苄胺、苄胺及各有机杂质组分,经紫外(206 nm)检测,用峰面积外标法测定对氟苄胺、邻氟苄胺、间氟苄胺及苄胺含量,有机杂质含量的测定采用峰面积归一化法。结果:对氟苄胺、邻氟苄胺、间氟苄胺及苄胺线性良好,回收率分别在99.7%～99.9%,99.5%～99.8%。结论:在该色谱条件下,对氟苄胺、邻氟苄胺、间氟苄胺及苄胺与杂质峰能获得完全分离,本方法测定速度快,结果准确,重现性好。     

Organocatalytic Enantioselective Michael Reaction of Malononitrile with β,β‐Disubstituted Nitroalkenes

We have developed and optimized an enantioselective Michael reaction of malononitrile with β,β‐disubstituted nitroalkenes. This reaction was catalyzed by a cinchona alkaloid derived thiourea catalyst, producing products of high yields (up to 98 %) and stereoselectivities (up to 93 % ee). One of the adducts was used as an intermediate for the synthesis of dihydropyrrole derivative bearing a synthetically valuable quaternary chiral center.