硒催化羰基化合成苯恶唑啉酮

Benzoxazolinones are a known class of commercially available compounds that are widely used in agriculture and industry. Traditionally, these compounds are made by the intramolecular cyclization of phenyl N-(2-hydroxyphenyl)carbamate which is produced by the reaction of o-aminophenol with phenyl chloroformate[1], this route needs a large number of steps from commercially available starting materials; another method is the reaction of o-aminophenol with much more urea, a lot of NH3 is released during the process[2,3]; the last method is from salicylic acid by treatment with hydroxylamine and commercial polyphosphoric acid, the yield of the reaction is 33%[4].     

Selenium-Catalyzed Oxidative Carbonylation of Aniline and Alcohols to N-Phenylcarbamates

A facile one-pot, phosgene-free synthesis of N-phenylcarbamates is demonstrated. Catalyzed by selenium, oxidative carbonylation of aniline with alcohols in the presence of carbon monoxide and oxygen affords the corresponding N-phenylcarbamates, mostly in fair to good yields. Selenium can be easily recovered because of its phase-transfer catalysis function.     

N-Heterocyclic Carbene-Palladium Complex Catalyzed Oxidative Carbonylation of Amines to Ureas

Palladium carbene shows high efficiency without any promoter on oxidative carbonylation of amines to ureas and a new type of palladium carbene complex containing both an aniline and an NHC ligands was found to be the active species for the reaction.     

2-硒代咪唑类化合物催化CO与胺的羰基化反应

首次研究了2-硒代咪唑类化合物催化的一氧化碳对胺的羰基化生成对称脲或噁唑啉-2-酮的反应,目标产物收率中等到良好.与传统的单质硒催化的羰基化反应相比,新催化体系有效避免了有恶臭气味的含硒化合物的产生.     

一种新颖而简易的硒催化合成硫代氨基甲酸酯的方法

 在硒催化下,苯胺和硫醇在一氧化碳和氧气作用下发生氧化羰基化反应直接生成相应的硫代氨基甲酸酯,收率从中等到良好. 反应在室温无溶剂条件下进行. 催化剂硒能方便地回收且能循环使用.     

硒催化的乙二胺、乙醇胺和环胺的氧化羰基化反应

研究了以硒粉作催化剂,一氧化碳为羰基化试剂的乙二胺、乙醇胺和一些环胺的羰基化反应,考察了氧化剂对反应的影响。发现氧气是该反应较好的氧化剂,而没有氧化剂存在时,几乎没有羰基化反应发生。在硒／氧化剂体系存在下,乙二胺和乙醇胺这样一些分子内具有相邻两个亲基团物质的羰基化反应易趋向于分子内羰基化形成较为稳定的五元环产物,产率和选择性较高;而环胺如哌啶和吗啡啉的羰基化可生成相应的四取代脲产物。对反应机理进行     

硒催化CO/H2O还原芳烃硝化物制苯胺及其衍生物的反应

由芳烃硝化物还原制芳胺及其衍生物是重要的有机合成过程。本文介绍了Se/CO/H2O反应体系,对近年来硒催化CO/H2O还原芳烃硝化物制苯胺及其衍生物的进展进行了总结和评述,并介绍了反应机理;重点介绍了硒催化CO/H2O还原反应从高压反应发展到常压反应的过程,指出在常压条件下使用硒催化CO/H2O还原体系还原芳烃硝化物制苯胺及其衍生物是一个很有应用前景的方法。     

硒催化法合成2-吡啶脲的研究

 采用硒催化的一氧化碳还原羰基化法,由硝基苯衍生物与2－氨基吡啶进行反应,得到的不是比例相当的三种脲类物质混合物,而主要得到非对称的吡啶脲．进一步发展了硒／一氧化碳催化体系对硝基化合物的还原羰基化法,可望用来合成一系列含取代基的苯基吡啶基脲类物质;该合成方法工艺简单,操作易行．对部分产物进行了红外光谱、核磁共振谱、高压液相色谱及元素分析等鉴定．     

Synthesis of Novel Unsymmetric Bisbenzimidazoles

Using chloroacetic acid, p‐hydroxyl aromatic aldehydes 1 and aromatic diamines 3 as starting materials, novel bisbenzimidazoles 5 with unsymmetric structure were synthesized via aryloxyacetic acid intermediates 2 . Four new intermediates 4 and ten target molecules 5 were characterized by FTIR, ¹H NMR, ¹³C NMR, MS and elemental analysis. Different synthetic methods, including one‐pot synthesis and intermittent microwave promotion, were investigated. The research provides a new method and idea for the synthesis of bisbenzimidazoles.     

反应过程相转移催化选择氧化还原羰基化合成N－亚戊基－N′－芳脲

N-pentamethylene-N′-aryl ureas are important fine chemical intermediates in industries of dye, pigment, pharmaceutical and pesticide. At present, their industrial synthesis uses phosgene which is of high toxicity[1,2].     

Stoichiometric Reactions of CO2 and Indium‐Silylamides and Catalytic Synthesis of Ureas

The indium compounds In(N(SiMe₃)₂)₂Cl⋅THF ( 2 ) and In(N(SiMe₃)₂)Cl₂⋅(THF)_n ( 3 ) were shown to react with CO₂ to give [(Me₃Si)₂N)InX(μ‐OSiMe₃)]₂ (X=N(SiMe₃)₂ 4 , Cl 5 ). 0.05–2.0 mol % of the species 3 acts as a pre‐catalyst for the conversion of aryl and alkyl silylamines under CO₂ (2–3 atm) to give the corresponding ureas in 70–99 % yields. A proposed mechanism is supported by experimental and computational data.     

硒催化CO/H2O还原1-硝基萘制1-萘胺

 以具有反应控制相转移特点和可回收再利用的硒为催化剂,以CO/H2O为还原剂,在常压条件下还原1-硝基萘制1-萘胺,考察了不同溶剂和碱对反应的影响. 结果表明,在极性非质子溶剂如二甲基甲酰胺中,以氢氧化钠为助催化剂时1-硝基萘可定量还原为1-萘胺.     

Synthesis of Unsymmetric Monosubstituted and Disubstituted Dinaphthothiophenes

Dinaphthothiophenes (DNTs) are a class of compounds with potential uses in organic semiconductors and the synthesis of unsymmetric catalysts. Symmetrical or asymmetrical addition of functional groups to the DNT structure may be desired for steric bulk in binaphthyl catalyst synthesis or tuning the electronic properties of semiconductors. Thus, versatility of functional group addition is a great asset in DNT synthesis. Until now, no versatile and concise methods for the synthesis of unsymmetrically substituted DNTs have been reported. Herein, we report three synthetic routes for the creation of three different classes of DNTs. Each route involves the successive addition of two functionalized styryl groups to a thiophene ring, followed by a photocyclization to form the desired asymmetric DNT. Various novel unsymmetrically monosubstituted and disubstituted dinaphtho[2,1‐b :1′,2′‐d ]thiophenes, dinaphtho[1,2‐b :1′,2′‐d ]thiophenes, and dinaphtho[1,2‐b :2′,1′‐d ]thiophenes were synthesized from 2‐bromothiophene,2,4‐dibromothiophene, and 3,4‐dibromothiophene in three or four steps. These methods can be used to synthesize a wide variety of unsymmetrically functionalized DNTs.     

Facile Synthesis of Ureas in Ionic Liquid

The urea functional group is of importance in a wide range of biological compounds such as enzyme inhibitors1 and pseudopeptides2. Substituted ureas are widely applied in fine chemical industry, especially pesticides3 and pharmaceuticals4. Many investigations have been made to search for an efficient and practical method to synthesize ureas. The typical procedure for the synthesis of ureas is treating isocyanates with primary or secondary amines in organic solvents5. In the presence of trans…     

氧化羰化法直接合成双酚A型聚碳酸酯

使用Pd系氧化还原催化体系氧化羰化双酚A和CO直接合成了聚碳酸酯。在PdCl20．016mmol,n(Pd)：n(Cu)：n(对苯醌)：n(四丁基溴化铵)=1：4：40：40,双酚A22mmol,CH2Cl250mL。4A分子筛4g,CO5．5MPa,O2O．5MPa,反应温度100℃,搅拌速度800rpm的条件下反应12h,得到的聚碳酸酯重均分子量M。为2450。探索了杂多酸和杂多酸的四丁基铵盐对氧化羰化双酚A直接合成聚碳酸酯的促进作用。使用Pd-Mn-(TBA)8SiW12O42啦催化剂体系,在上述相同的实验条件下反应8h,得到的聚碳酸酯重均分子量Mw为2225,好于Pd-Cu-苯醌催化体系的结果(Mw=1720)。对合成得到的聚碳酸酯进行了IR光谱分析,并通过与相同条件下得到的商品聚碳酸酯(Mw=22000)的IR光谱对照,对实验结果进行了确认。     

氨基甲酸酯类化合物的合成方法改进

将Alper羰基化合成氨基甲酸酯的实验改在高压釜中进行 ,并且充入的气体量只比化学量稍过量 ,在没有盐酸或Lewis酸的作用下 ,伯胺和仲胺都得到了非常高的转化率和非常高的选择性 ,特别仲胺的转化率和选择性比文献报道有很大提高。     

Synthesis and Bioactivity of Novel Fluorinated Heteroaromatic Ureas

In order to find new urea cytokinins, a series of novel fluorinated heteroaromatic ureas have been designed and synthesized. The crystal structure of 3g was further determined by single crystal X-ray diffraction to obtain the structural feature of this class of urea compounds. The preliminary bioassay showed that some title compounds have good cytokinin activity.     

Recent Advances in Homogeneous Carbonylation Using CO2 as CO Surrogate

Carbon dioxide is a sufficient and important carbon resource, which has been widely used as a C1 building block in synthetic chemistry. Carbonylations with CO are important processes in industry. However, due to the toxicity of CO, its storage and transport are problematic. Attentions are gradually focused on using other safe reagents to be the CO surrogates in carbonylation reactions. This review focuses on the summary of recent developments in using CO₂ as a CO surrogate in homogeneous catalysis. Reductive processes by using H₂, Si‐H, alcohols, etc and redox‐neutral processes are separately summarized.