一个简单、环境友好的硅胶固载硫酸催化Biginelli反应体系(英文)

A protocol for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and-thiones was developed by means of a three-component condensation of an aldehyde,a β-dicarbonyl compound,and urea or thiourea in acetic acid catalyzed by silica-bonded S-sulfonic acid.Compared to the classical Biginelli reaction conditions,this new protocol has the advantages of consistently excellent yields and short reaction times.After the reaction,the catalyst could be recovered easily and reused with little change in its activity.     

Preparation of Silica-Bonded S-Sulfonic Acid: A Recyclable Catalyst for the Synthesis of Bis-Indolylmethanes

Silica bonded S-sulfonic acid (SBSSA) was prepared by the reaction of 3-mercaptopropylsilica (MPS) and chlorosulfonic acid in chloroform. Silica-bonded S-sulfonic acid, as a reusable solid acid catalyst, was used for the condensation reactions of indole with carbonyl compounds at ambient temperature. Tetra-(indolyl)methanes were also obtained by the condensation reaction of indole with dialdehyde compounds. Silica bonded S-sulfonic acid was recovered and reused.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

硅胶键合N-丙基二乙烯氨基磺酸作为可回收固体酸催化剂催化合成α-氨基腈(英文)

Silica-bonded N-propyl diethylenetriamine sulfamic acid (SBPDSA) is employed as a recyclable catalyst to synthesize α-aminonitriles. These syntheses involved one-pot condensation of an aldehyde, an amine, and trimethylsilyl cyanide under mild reaction conditions at room temperature. SBPDSA was recycled seven times in the condensation of benzaldehyde, aniline, and trimethylsilyl cyanide without reduction of its catalytic activity.     

Efficient synthesis of symmetrical bisamides catalyzed by reusable hydroxyapatite

Efficient synthesis of symmetrical bisamides is achieved by hydroxyapatite catalyst. Hydroxyapatite catalyzes the reaction between aldehydes and amides to afford bisamides at reflux conditions in 87–95% yields in acetonitrile medium. The catalyst is readily recovered and reused at least three times without loss in its catalytic activity. This method is noteworthy that, symmetrical bisamides are synthesized by fast, simple, effective, and environmentally benign heterogeneous protocol.     

Synthesis of gem-Dihydroperoxides from Ketones and Aldehydes Using Silica Sulfuric Acid as Heterogeneous Reusable Catalyst

Silica sulfuric acid (SSA) was found to efficiently catalyze the conversion of aldehydes and ketones directly into the corresponding gem-dihydroperoxides (DHPs) on treatment with aqueous 30% H₂O₂ at room temperature. Mild reaction conditions, good to excellent yields, short reaction times, low environmental impact, and recyclability of the catalyst are the main advantages of this synthetic method.     

磁性纳米粒子负载钯催化有机合成反应研究进展

磁性纳米粒子负载钯催化的有机合成反应,由于具有催化活性高,催化剂在外加磁场作用下即可快速分离和重复使用等特点,已引起了人们的广泛关注.综述了近年来磁性纳米粒子负载钯催化有机合成反应的研究进展,载体包括Fe3O4纳米粒子、有机小分子修饰的磁性纳米粒子、SiO2包覆的磁性纳米粒子、碳修饰磁性纳米粒子、羟基磷灰石包覆的磁性纳米粒子和有机高分子修饰的磁性纳米粒子等.     

氮掺杂的有序介孔碳负载钴纳米颗粒用于脂肪酰胺的催化加氢

酰胺的选择性加氢可以作为有机胺的一种生产路径。传统的酰胺加氢多相催化体系多采用贵金属催化剂和高压氢气,存在成本较高的问题。本文采用离子交换热解法制备了氮掺杂有序介孔碳负载钴纳米颗粒催化剂(Co/MNC),该催化剂在脂肪族酰胺加氢反应中表现出良好的活性和选择性。结果表明,负载型Co催化剂在500 °C下热解后,Co纳米颗粒分散均匀,催化剂表面同时存在金属Co0和具有路易斯酸性的CoOx,催化性能明显优于Co/MNC-H600和Co/MNC-H700     

腐殖酸催化醛高效快速合成腈

腐殖酸是一种无毒、非金属、价格低廉和来源广泛的大分子有机物质。以腐殖酸为催化剂,N-甲基吡咯烷酮（NMP）为溶剂,由醛和盐酸羟胺反应合成了腈类化合物。研究了催化剂用量、溶剂、反应温度等因素对产率的影响。实验结果表明：醛1.0 mmol,盐酸羟胺1.2 mmol,催化剂腐殖酸0.1 g, NMP 2 mL,在110 ℃下...     

Highly Efficient Dehydrogenative Coupling of Hydrosilanes with Amines or Amides Using Supported Gold Nanoparticles

Hydroxyapatite‐supported gold nanoparticles (Au/HAP) can act as a highly active and reusable catalyst for the coupling of hydrosilanes with amines under mild conditions. Various silylamines can be selectively obtained from diverse combinations of equimolar amounts of hydrosilanes with amines including less reactive bulky hydrosilanes. This study also highlights the applicability of Au/HAP to the selective synthesis of silylamides through the coupling of hydrosilanes with amides, demonstrating the first example of an efficient heterogeneous catalyst. Moreover, Au/HAP shows high reusability and applicability for gram‐scale synthesis.     

酰胺类化合物的高效合成研究

酰胺类化合物是有机化学中最常见的化合物之一, 在药物化学、生物化学以及高分子合成等领域都有着重要的应用. 近年来高效合成酰胺类化合物已经成为一个研究热点, 具有重要的意义.本文主要从过渡金属催化、有机小分子催化等方面讨论近几年来酰胺类化合物的合成研究进展, 并对其发展趋势进行展望.     

Efficient Synthesis of Readily Water-Soluble Amides Containing Sulfonic Groups

A series of various readily water-soluble amides were synthesized by different procedures. These compounds are useful chemical tracers for assessing the cooling progress in a georeservoir during geothermal power plant operation. Acylation of primary amines was carried out by basically employing the Schotten–Baumann method. As a second method a single-phase solvent system consisting of ethyl acetate as an organic solvent and triethylamine as a catalyst was used. Products were characterized by ¹H NMR and ¹³C NMR.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

An Efficient and Practical Procedure for Synthesis of 1,1‐Diacetates from Aldehydes Catalyzed by Zirconium Sulfate Tetrahydrate–Silica Gel

Abstract

A facile and efficient procedure for synthesis of 1,1‐diacetates from aldehydes with acetic anhydride was described using zirconium sulfate tetrahydrate–silica gel as catalyst in excellent yields under mild reaction conditions.     

新型含苯并噻唑基双酰胺衍生物的合成及其抗菌活性

以邻甲基苯甲酸和取代邻氨基苯甲酸为起始原料,设计并合成了10个未见文献报道的含苯并噻唑基双酰胺类衍生物,其结构经1H NMR,13C NMR,IR及元素分析表征。初步的抗菌活性测试结果表明,在500 mg.L-1浓度下部分化合物对黄瓜花叶病毒(CMV)有一定抑制作用。     

Synthesis of Amides and Phthalimides via a Palladium Catalyzed Aminocarbonylation of Aryl Halides with Formic Acid and Carbodiimides

A novel method for the preparation of amides and phthalimides has been developed. The process involves a palladium catalyzed aminocarbonylation of an aryl halide, using a carbodiimide and formic acid as the carbonyl source. Experimental data suggest that the mechanistic pathway for this process involves in‐situ generation of carbon monoxide from the reaction of formic acid with a carbodiimide in the presence of a palladium catalyst. The method can be used to produce a variety of amides and N‐substituted phthalimides efficiently.     

Amidation of Aryl Halides Catalyzed by the Efficient and Recyclable Cu2O Nanoparticles

Cu₂O nanoparticles/DMEDA (N,N′‐dimethylethylenediamine) was proved to be an efficient catalyst system for amidation of aryl halides under mild condition. This method displayed excellent selectivity and the catalyst was recyclable without loss of activity. The low cost, simple operation and excellent yields make this approach attractive for industrial applications.     

A Versatile and Practical Synthesis of 1,1‐Diacetates from Aldehydes Catalyzed by Cyanuric Chloride

Structurally diverse aldehydes are successfully converted into 1,1‐diacetates with acetic anhydride using cyanuric chloride as a mild, convenient and inexpensive catalyst under solvent‐free conditions. The noteworthy features of the present system are shorter reaction times, and mild and solvent‐free conditions. Furthermore, it offers chemoselective protection of aldehydes.     

固体酸催化合成邻苯二甲酸二戊酯的研究

以苯酐和正戊醇为原料,采用自制的固体酸SO4^2-／SiO2、SO4^2-／Fe2O3、SO4^2-／SnO2及SO4^2-／TiO2作为催化剂合成邻苯二甲酸二戊酯（DAP）,分别考察固体酸催化剂的种类、固体酸催化剂的用量、醇酐比、反应时间等因素对合成DAP产率的影响。实验结果表明,其优化的工艺操作条件为：苯酐0．1mol,固体酸催化剂SO4^2-／SiO2 1．7g,醇酐比2．4：1,带水剂二甲苯20mL,反应时间3．5h,其产品收率达91．3％以上。SO4^2-／SnO2作为该反应的催化剂具有催化活性高、寿命长、可多次重复使用、产物易纯化分离且产品色泽浅等优点,可望代替传统的浓硫酸作催化剂应用于DAP的合成。     

An Efficient Zinc‐Catalyzed Dehydration of Primary Amides to Nitriles

In the present study, the zinc‐catalyzed dehydration of a variety of amides with N‐methyl‐N‐(trimethylsilyl)trifluoroacetamide (MSTFA) as a dehydration reagent into the corresponding nitriles has been examined in detail. With the straightforward and commercially available zinc(II)triflate as the precatalyst and MSTFA, an excellent system has been established to afford nitriles in excellent yields and chemoselectivities. After investigation of reaction conditions and the scope and limitations, several efforts were carried out to understand the reaction mechanism.