Synthesis and Characterization of Novel Multifunctional Acylthiourea Polymers

Several thiourea polymers have been synthesized through the reaction of diamine with 1, 4-or 1, 3-benzenedicarbonyl chloride and ammonium thiocyanate by solid-liquid phase transfer catalysis of polyethylene glycol-400 (PEG-400). The polymers were characterized and identified by elemental analysis, IR, HNMR and GPC. The multifunctional polymers have potential value as an ideal support for immobilized enzymes.     

Green organic syntheses: organic carbonates as methylating agents

Dimethylcarbonate (DMC) is a valuable methylating reagent that can replace methyl halides and dimethylsulfate in the methylation of a variety of nucleophiles. It couples tunable reactivity and unprecedented selectivity towards mono-C- and mono-N-methylation. In addition, it is a prototype example of a green reagent, because it is nontoxic, is made by a clean process, is biodegradable, and reacts in the presence of a catalytic amount of base, thereby avoiding the formation of undesirable inorganic salts as by-products. Depending on the reaction conditions, DMC can be reacted under plug-flow, CSTR, or batch conditions. Other remarkable reactions are those where DMC behaves as an oxidant. The reactivity of other carbonates is reported as well.     

醋酸溶液中2,3-二芳基-喹喔啉的简便合成

1,2-二芳基乙二酮与1,2-苯二胺在室温醋酸溶液中反应数分钟,生成2,3-二芳基一喹喔啉.反应时间短(1～10min),产率高(90%～97%),反应条件温和,操作简便.     

Pickering Interfacial Catalysis for Biphasic Systems: From Emulsion Design to Green Reactions

Pickering emulsions are surfactant‐free dispersions of two immiscible fluids that are kinetically stabilized by colloidal particles. For ecological reasons, these systems have undergone a resurgence of interest to mitigate the use of synthetic surfactants and solvents. Moreover, the use of colloidal particles as stabilizers provides emulsions with original properties compared to surfactant‐stabilized emulsions, microemulsions, and micellar systems. Despite these specific advantages, the application of Pickering emulsions to catalysis has been rarely explored. This Minireview describes very recent examples of hybrid and composite amphiphilic materials for the design of interfacial catalysts in Pickering emulsions with special emphasis on their assets and challenges for industrially relevant biphasic reactions in fine chemistry, biofuel upgrading, and depollution.     

A Novel Synthesis of Diethyl Malonate

Diethyl malonate (DEM) is an important starting material in pharmaceutical and agricultural chemical industries. Traditional synthetic method by reaction mono chloroacetic acid with sodium cyanide1 is unfriendly to environment and involves complicated procedures. Therefore, green synthesis routes of diethyl malonate were investigated actively in past decade. There have been proposed various processes for preparing DEM by carbonylation of ethyl chloroacetate catalyzed by Co2(CO)82, 3. Howev…     

Synthesis of the Novel Chiral Catalysts by Click Chemistry and Their Application

Novel cinchonine ammonium salt derivatives have been prepared by 1,3‐dipolar cycloaddition. Their chiral catalytic efficacy was investigated in the asymmetric alkylation of N‐diphenylmethyleneglycine t‐butyl ester in the water phase. As the special structure of the catalyst, its asymmetric alkylation catalytic behavior both in organic solvents and in water is satisfactory, which is environmentally friendly.     

Synthesis and Bioactivity of Some Novel 5-Arylmethylideneamino-1,3,4-Thiadiazole-2- Ylthioacetanilide Derivatives

Abstract

Some novel of 5-arylmethylideneamino-1,3,4-thiadiazole-2-ylsulfanyl acetamide derivatives were synthesized by the S-alkylation of 5-arylmethylideneamino-2-mercapto-1,3,4-thiadiazoles with chloroacetyl anilide under solid–liquid phase transfer catalysis using polyethylene glycol-400 (PEG-400) catalyst in the presence of potassium carbonate. Some of the title compounds were investigated for plant growth-regulating activity. They were found to enhance root elongation remarkably at a low concentration.

[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 following free supplemental files: Additional figures and tables].     

Broader,Greener, and More Efficient: Recent Advances in Asymmetric Transfer Hydrogenation

Asymmetric transfer hydrogenation has become a practically useful tool in reduction chemistry in the last decade or so. This was largely triggered by the seminal work of Noyori and co‐workers in the mid‐1990s and is driven by its complementing chemistry to hydrogenation employing H₂. This Focus Review attempts to present a “holistic” overview on the advances in the area, focusing on the achievements recorded around the last three years. These include more‐efficient and “greener” metal catalysts, catalysts that enable hydrogenation as well as transfer hydrogenation, biomimetic and organocatalysts, and their applications in the reduction of C?O, C?N, and C?C bonds. Also highlighted are efforts in the development of environmentally benign and reusable catalytic systems.     

Synthesis of N-benzoyl-N''-aryl selenoureas under PTC

Recently many syntheses of selenium-containing compounds have been reported and studied, in which compounds selenoureas are used as the precursors for the syntheses of selenium-nitrogen heterocyclic compounds and their activities have received increasing attentions.Herein, we report the facile preparation of N-benzoyl-N'-aryl selenourea derivatives using potassium selenocyanate.In this typical procedure, Benzoyl chloride 1 was treated with potassium selenocyanate in CH2C12 under the condition of solid-liquid phase transfer catalysis using polyethylene glycal-400 as the catalyst to give the corresponding benzoyl isoselenocyanate 2. This compound did not need to be isolated and reacted with aromatic amine affording the N-benzoyl-N'-aryl selenourea derivatives 3.The reaction is described as:All the experiments were carried out under the condition of solid-liquid phase transfer catalysis using polyethylene glycal-400 as the catalyst and room temperature. And the structure was determined by IR, 1H NMR and 13C NMR. Selected data for N-benzoyl-N'-(4-fluoro)-selenourea:IR(KBr) 3426, 3274, 1672,1234,1155(C=Se); 1HMR(500MHz, DMSO) δ 12.85 (1H,S),11.86(1H,S), 7.27(2H,d,J=2.15), 7.98(2H,s,J=l.15), 7.30(2H,d,J=2.05), 7.56(2H.t,J=6.50),7.67(1H,t,J=6.20); 13C NMR(500MHz, DMSO)δ 181,168(C=Se),135,133, 132,115, 128.3, 128.8,161, 129.     

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.     

新型吲哚苯醌衍生物的合成及抗肿瘤活性

基于醌类以及含"2-苯基萘型"结构单元的衍生物在临床上表现出良好的抗肿瘤活性,设计了取代吲哚苯醌衍生物。以2-取代吲哚衍生物为底物,乙腈为反应溶剂,在相转移催化剂苄基三乙基氯化铵和无水碳酸钾存在下,与四溴苯醌反应,合成了9个未见文献报道的2-取代吲哚-1,4-醌衍生物(2a^2c,3a^3c,4a^4c),其结构经1H NMR,13C NMR和HR-MS(ESI)表征。体外抗肿瘤活性实验表明,该类化合物对人肺癌细胞系(A549)、人乳腺癌细胞系(MDA-MB-231)及宫颈癌细胞系(Hela)具有抑制作用,其中化合物2b和3c对人乳腺癌细胞系MDA-MB-231具有良好的抑制活性。