在碲氢化钠作用下一步合成仲胺

本文报道合成仲胺的简便方法。在碲氢化钠(NaHTe)作用下,芳香族或脂肪族伯胺与醛反应,一步生成相应的仲胺。     

碲氢化钠还原亚胺的方法

本文报道一种还原亚胺的新方法。取代的芳基和脂肪基亚胺可以在较温和的条件下被碲氢化钠顺利地还原为相应的仲胺。     

羧酸经苯并咪唑还原为醛的新合成方法研究

羧酸经苯并咪唑还原为醛的新合成方法研究史真顾焕（西北大学化学系西安７１００６９）醛是一类重要的有机化合物，无论是在有机化学的基础研究还是应用研究中，醛类化合物都占有特殊的重要地位。醇的氧化是制备醛的主要方法之一。以羧酸为原料，通过羧酸衍生物的还原得到...     

碲氢化钠与胺烷基化苯并三氮唑的反应

碲氢化钠是一个用途广泛的磁试剂,自作为有用的去溴试剂以来,日益受到化学工作者的关注,不断有文献报道它的合成及应用.例如能有效地还原卤代烃、硝基化合物、叠氮化合物和亚胺等.近年来,Katritzky报道了胺烷基化苯并三氮唑衍生物的合成及应用,此衍生物中的苯并三氮唑基是很好的离去基团,易被各种亲核试剂所取代.我们在前文中对硒氢化钠与胺烷基化苯并三氮唑反应生成二苄基二硒醚的合成进行了报道.本文用碲氢化钠与胺烷基化苯并三氮唑反应,结果生成还原产物N-取代胺.     

过渡金属盐促进的纳米氢化钠对硝基的还原反应

研究了在过渡金属盐促进下，纳米尺寸的活性氢化钠对硝基化合物的还原反应．结果表明，过渡金属盐的存在，使纳米氢化钠（ＮａＨ＊）的还原活性进一步增强，硝基苯的转化率在较短时间内就超过９０％．镍盐对生成苯胺的选择性最好（１００％），其次是锰盐．不同纳米碱金属氢化物对硝基苯还原的活性和生成苯胺的选择性顺序为ＮａＨ＊＞ＫＨ＊＞ＬｉＨ＊．几种硝基化合物的反应结果表明，ＮａＨ＊－镍盐是硝基还原生成芳胺有效的复合还原剂     

通过烯丙基碲盐合成烯丙基硫醚的新方法

本文阐述了室温下,在NaOH存在下, 烯丙基二烃基溴化亚碲经苯硫酚或硫代烷基处理, 可高产率地得到烯丙基硫醚. 这一过程提供了一个有效的合成烯丙基硫醚的新方法.     

苯乙醛和对甲氧基苯甲醛的新合成方法

苯乙醛;对甲氧基苯甲醛;二甲基取代苯并咪唑盐;碲氢化钠     

碲氢化钠存在下3—氧化硫代羧酸酯的一步合成法

３－氧代硫代羧酸酯可由α－溴代酮与碲氢化钠作用形成的烯醇盐与二硫代碳酸二乙酯进行乙氧硫代羰基化反应制得，３－氧代硫代羧酸酯的烯醇含量可由核磁振谱测得。     

邻苯二胺与醛反应合成苯并咪唑衍生物的反应机理研究

以4-甲基苯甲醛与邻苯二胺反应合成2-(4-甲基苯基)苯并咪唑的反应为例,以HPLC方法跟踪反应进程,对关键中间体与产物的结构通过1H NMR,FT-IR及LC-MS等手段进行了表征.实验证明了在邻苯二胺和醛物质的量比为1:1时同时生成单席夫碱和双席夫碱中间体的反应机理,并提出了该类反应的影响规律.     

Novel synthetic method for ketones from substituted benzimidazolium salts and Grignard reagents

A new synthetic method of ketones from substituted benzimidazolium salts and Grignard reagents is reported. The influences of the various Grignard reagents on the yield of ketones and the mechanism are discussed.     

一种高效、洁净的还原醛的新方法

报道了在超临界CO2中，实现氢转移反应的新方法，这一方法以水为氢授体， 锌粉为电子授体，高选择性地还原对甲基苯甲醛为相应的醇，并初步研究了反应温 度、反应体系中CO2的压力、反应时间对还原反应的转化率的影响。     

A novel method for the formylation of Grignard reagent

A facile and efficient method for the formylation of Grignard reagent was reported, and a new approach for the preparation of aldehydes from Grignard reagent and benzimida-zolium salts was provided.     

Preparation and Intramolecular CC Coupling Reaction for Bis‐benzimidazolium Salt

Bis‐benzimidazolium salt 1 was prepared via a series of reactions using 2,2′‐diphenol as starting material. Compound 2 was afforded through the intramolecular C? C coupling reaction of 1 under the catalysis of Pd(OAc)₂. The structure of 2 is characterized through X‐ray diffraction analyses, ¹H NMR and ¹³C NMR. In 2 , two boat‐like seven‐membered rings are contained, where the C? C bond distance newly formed is 1.461(5) Å, and it is between regular C? C single bond (1.54 Å) and C?C double bond (1.34 Å). This shows that new C? C bond has partial double‐bond character. In the crystal packing of 2 , the 2D supramolecular layers are formed via C? H···F hydrogen bond.     

The Synthesis of Dialdehyde from Sodium Hydrogen Telluride with 1,1'''',3,3''''-Tetramethyl-2,2''''-bis-benzimidazolium Salt

Dialdehydes are important chemical industrial materials. An efficient preparation method of dialdehydes has been interested. We have reported two novel synthetic methods of dialdehyde via the addition-hydrolysis reaction of benzimidazolium salt with bis-Grignard reagent1 and the reduction-hydrolysis reaction of diimidazoline2. Sodium hydrogen telluride has been shown to be a convenient reagent for the reduction of unsaturated nitro-compounds to saturated ones3. The reduction of N-methylpy…     

One-step synthesis ofα,β-unsaturated arylsulfones by a novel multicomponent reaction of aromatic aldehydes,chloroacetonitrile, benzenesulfinic acid sodium salt

A new and green method for the synthesis of α,β-unsaturated arylsulfones had been achieved through the condensation of aromatic aldehydes,chloroacetonitrile,benzenesulfinic acid sodium salt in the presence of l-butyl-3-methyl imidazolium hydroxide([bmim]OH) in EtOH under reflux.The ionic liquid was recovered and recycled for subsequent reactions.The advantages of this protocol were non-toxic,easy work-up and good yields.     

Efficient synthesis of triarylmethanes via bisarylation of aryl aldehydes with arenes catalyzed by silica gel-supported sodium hydrogen sulfate

An efficient synthesis of triarylmethanes has been developed via bisarylation of aryl aldehydes with arenes catalyzed by silica gel-supported sodium hydrogen sulfate in a solvent-free system. The new method features high yield, mild reaction conditions, and environmental friendliness.     

Bis(benzimidazolium)methane salts: a potential guest for dibenzo-24-crown-8 towards [2]pseudorotaxanes

We investigated the threading of bis(benzimidazolium) methane moieties with DB24C8 at 35 °C (room temperature) and found a high degree of association. The presence of threaded complexes was determined by ¹H NMR and also supported by high resolution mass spectrometry and B3LYP/6-31G**++calculations. A 2D NMR study was done to elucidate the host-guest geometry and the molecular interactions present. The variable temperature NMR experiment was done over a temperature range of 243-323 K. The threading was stable and visible even at 323 K. Acid-base equilibrium established the reversibility of the process. DFT optimized structures establish that two H-bonded links are present between O₁?O_4′ and O₃?O_2′ across the dibenzo axis of the crown.     

Temperature dependence of fractionation of hydrogen isotopes in aqueous sodium chloride solutions

The D/H ratios of hydrogen gas in equilibrium with aqueous sodium chloride solutions of 2, 4 and 6 molalities were determined within the range 10 to 95°C, using a hydrophobic platinum catalyst. With each of the different sodium chloride concentrations, the hydrogen isotope effect between the solution and pure water changes linearly with the square of the reciprocal temperature. On the basis of the results for hydrogen isotope fractionation observed in this study, and those of hydrogen isotope fractionation between pure water and vapor, it is concluded that the structure of the aqueous sodium chloride solution does not change significantly with temperature. The hydrogen isotope effect is evidently different from the results of vapor pressure isotope effects (VPIE) on sodium chloride solutions measured on separated isotopes. The difference between the present work and the VPIE studies is probably due to a non-ideal behavior in a mixture of isotopic water molecules and/or to a H₂O-D₂O disproportionation reaction in sodium chloride solutions. The distinction between the latter two mechanisms can not be differentiated at present.     

An expedient esterification of aromatic carboxylic acids using sodium bromate and sodium hydrogen sulfite

Treatment of aromatic carboxylic acids and substituted toluenes with a mixture of sodium bromate and sodium hydrogen sulfite in a two-phase system gave the corresponding esters in good yield. The intermediate α-brominated toluene was formed by the in situ generated hypobromous acid. The α-bromotoluene underwent an intermolecular nucleophilic substitution reaction with aromatic carboxylic acids present in the reaction mixture to afford the corresponding esters.