Rethinking amide bond synthesis

One of the most important reactions in organic chemistry--amide bond formation--is often overlooked as a contemporary challenge because of the widespread occurrence of amides in modern pharmaceuticals and biologically active compounds. But existing methods are reaching their inherent limits, and concerns about their waste and expense are becoming sharper. Novel chemical approaches to amide formation are therefore being developed. Here we review and summarize a new generation of amide-forming reactions that may contribute to solving these problems. We also consider their potential application to current synthetic challenges, including the development of catalytic amide formation, the synthesis of therapeutic peptides and the preparation of modified peptides and proteins.     

兰州大学有机合成化学研究综述

简述了有机合成化学在有机化学学科中的地位和作用，通过回溯兰州大学有机合成化学领域科学研究的发展过程，展示了我校在有机合成化学发展史上的主要成就，并以若干最具代表性的研究成果，揭示了兰州大学有机合成化学的研究水平及其在学术界的地位和影响，反映了４０多年来兰州大学几代有机合成化学家积极追求科学真理的精神风貌。同时提出了我校今后一个时期里有机合成成化学领域科学研究的发展方向。     

Control of four stereocentres in a triple cascade organocatalytic reaction

Efficient and elegant syntheses of complex organic molecules with multiple stereogenic centres continue to be important in both academic and industrial laboratories. In particular, catalytic asymmetric multi-component 'domino' reactions, used during total syntheses of natural products and synthetic building blocks, are highly desirable. These reactions avoid time-consuming and costly processes, including the purification of intermediates and steps involving the protection and deprotection of functional groups, and they are environmentally friendly and often proceed with excellent stereoselectivities. Therefore, the design of new catalytic and stereoselective cascade reactions is a continuing challenge at the forefront of synthetic chemistry. In addition, catalytic cascade reactions can be described as biomimetic, as they are reminiscent of tandem reactions that may occur during biosyntheses of complex natural products. Here we report the development of an asymmetric organocatalytic triple cascade reaction for the synthesis of tetra-substituted cyclohexene carbaldehydes. This three-component domino reaction proceeds by way of a catalysed Michael/Michael/aldol condensation sequence affording the products with good to moderate yields (25-58 per cent). During this sequence, four stereogenic centres are formed with high diastereoselectivity and complete enantioselectivity. In addition, variation of the starting materials can be used to obtain diverse polyfunctional cyclohexene derivatives, which can be used as building blocks in organic synthesis.     

Carbon-heteroatom bond formation catalysed by organometallic complexes

At one time the synthetic chemist's last resort, reactions catalysed by transition metals are now the preferred method for synthesizing many types of organic molecule. A recent success in this type of catalysis is the discovery of reactions that form bonds between carbon and heteroatoms (such as nitrogen, oxygen, sulphur, silicon and boron) via complexes of transition metals with amides, alkoxides, thiolates, silyl groups or boryl groups. The development of these catalytic processes has been supported by the discovery of new elementary reactions that occur at metal-heteroatom bonds and by the identification of factors that control these reactions. Together, these findings have led to new synthetic processes that are in daily use and have formed a foundation for the development of processes that are likely to be central to synthetic chemistry in the future.     

Biologically inspired oxidation catalysis

The development of processes for selective hydrocarbon oxidation is a goal that has long been pursued. An additional challenge is to make such processes environmentally friendly, for example by using non-toxic reagents and energy-efficient catalytic methods. Excellent examples are naturally occurring iron- or copper-containing metalloenzymes, and extensive studies have revealed the key chemical principles that underlie their efficacy as catalysts for aerobic oxidations. Important inroads have been made in applying this knowledge to the development of synthetic catalysts that model enzyme function. Such biologically inspired hydrocarbon oxidation catalysts hold great promise for wide-ranging synthetic applications.     

稀土在挥发有机物催化净化技术领域的应用

 稀土因独特的化学性质，在挥发性有机物（VOCs）催化净化技术领域的基础研究和实际工程中应用十分广泛。综述了稀土材料在VOCs催化净化的研究机理和应用进展，并结合中国目前VOCs治理现状，探讨了其存在的问题及应对措施。     

Efficient Synthesis of Optically Active Alcohols

1 Introduction Optically active secondary alcohols are versatile building blocks for synthesis of unnatural biological active compounds and functional materials. Therefore, study on efficient synthesis of optically active alcohols is becoming an important subject in synthetic organic chemistry. Catalytic asymmetric reduction of carbonyl compounds is a practical method to create chiral alcohols. For the past decades, a large number of catalytic methods have been developed to achieve this goal. …     

有机小分子催化不对称环氧化

光学活性的环氧化合物是有机合成的重要原料.不对称环氧化反应可以使潜手性的烯烃转化为带有手性碳的环氧化合物,这个反应在医药、农药、香料等合成上具有重要的意义.有机小分子催化烯烃的不对称环氧化是一种高效,绿色的光学活性环氧化合物的合成方法,目前该类反应主要是通过手性酮和手性亚胺盐来催化实现的.文章介绍了该类反应的催化机理,并概述了这两类有机小分子催化的不对称环氧化反应的研究进展.     

Industrial biocatalysis today and tomorrow

The use of biocatalysis for industrial synthetic chemistry is on the verge of significant growth. Biocatalytic processes can now be carried out in organic solvents as well as aqueous environments, so that apolar organic compounds as well as water-soluble compounds can be modified selectively and efficiently with enzymes and biocatalytically active cells. As the use of biocatalysis for industrial chemical synthesis becomes easier, several chemical companies have begun to increase significantly the number and sophistication of the biocatalytic processes used in their synthesis operations.     

杂多化合物在催化反应中的应用研究

本文分别从以下三个方面对杂多化合物的催化作用进行概括：1、主要应用在石油化工方面的烃类的烷基化和异构的酸催化功能;2、应用在配合氧化剂催化烯烃的环氧化反应和燃油脱硫氧化还原催化功能;3、在有机合成中的酯化反应方面的氧化还原催化功能.     

MCM-41中孔分子筛研究进展

MCM 4 1中孔分子筛具有极高的BET比表面积、均一的中孔结构等特点 ,可广泛用于催化、吸附脱附、分离和传感技术等领域。从合成方法、合成条件的影响、辅助添加剂对分子筛的改性以及合成机理等方面对MCM 4 1中孔分子筛的研究进展进行了综述。着重分析了MCM 4 1中孔分子筛的水热稳定性差、酸性弱等问题 ,并提出了相应的解决方法 ,重点介绍了MCM 4 1中孔分子筛增大孔径的几种方法———改变合成条件、添加增孔剂、水热合成后处理、改换模板剂等。对MCM 4 1中孔分子筛在石油化工催化领域中的应用现状及前景进行了分析 ,提出了应在改善MCM 4 1中孔分子筛的热稳定性及水热稳定性、开发合成更大孔径分子筛、研究新型模板剂等方面加强研究。     

林产化工专业有机高分子合成创新教学探索

林产化工专业是应用性较强的专业,将理论教学与实验教学相结合,是实现创新人才培养目标的重要教学环节。针对有机高分子合成化学课程中存在的问题,结合林产化工专业发展的现状,为了深化教学改革,从添加最新的相关教学内容、引入科技研究前沿动态、采用现代教育理念,引导学生自主学习入手,并在观念上重视实验课程,进行实验课程改革,新开设了研究设计性实验课,考核评定上要合理灵活,才能使本科生有机高分子合成化学教学符合我国现有林产化工的发展趋势,为全面培养学生严谨的科学态度、良好的实验素质的创新能力提供新思路。     

聚乙二醇支持的CuI催化Huisgen环加成反应合成三氮唑(英文)

我们发展了聚乙二醇(PEG4000)支持的CuI催化的Huisgen环加成反应合成三氮唑衍生物的新颖方法.在聚乙二醇(PEG4000)支持的CuI的催化下,芳基叠氮和末端炔的Huisgen环加成反应以较高的收率得到三氮唑衍生物.初步研究负载催化剂的回收使用情况.     

兼具光催化和化学催化双重活性的Pt-TiO2薄膜

采用提拉-光沉积两步法制得了一种新的铂化TiO2光催化薄膜,实验结果表明该光催化薄膜对甲酸的降解同时具有光催化和化学催化双重活性,因此,纳米Pt的化学催化作用可作为增强TiO2光催化氧化有机污染物效率的一种新的机理.     

VOCs催化反应过程与反应机理研究现状

论述了挥发性有机污染物(VOCs)催化反应过程机理研究的现状,包括催化剂的表征、催化过程研究方法以及不同的研究体系。催化剂表征使用原位技术以及X射线吸收精细结构(XAFS)方法可以更好地阐述催化剂在催化过程中的作用与机制。催化过程研究主要包括催化反应动力学模拟(Power-rate Law、Mars-van Krevelen Model、Langmuir-Hinshelwood),反应产物监测(原位红外技术、原位核磁技术、暂态技术、同位素示踪技术),量子化学计算等。其中,反应动力学是使用较为广泛的研究催化反应机制的技术之一。反应产物监测可以得到直观的认识,获得了广大学者的关注。量子化学计算只作为论证。     

Synthetic homeostatic materials with chemo-mechano-chemical self-regulation

Living organisms have unique homeostatic abilities, maintaining tight control of their local environment through interconversions of chemical and mechanical energy and self-regulating feedback loops organized hierarchically across many length scales. In contrast, most synthetic materials are incapable of continuous self-monitoring and self-regulating behaviour owing to their limited single-directional chemomechanical or mechanochemical modes. Applying the concept of homeostasis to the design of autonomous materials would have substantial impacts in areas ranging from medical implants that help stabilize bodily functions to 'smart' materials that regulate energy usage. Here we present a versatile strategy for creating self-regulating, self-powered, homeostatic materials capable of precisely tailored chemo-mechano-chemical feedback loops on the nano- or microscale. We design a bilayer system with hydrogel-supported, catalyst-bearing microstructures, which are separated from a reactant-containing 'nutrient' layer. Reconfiguration of the gel in response to a stimulus induces the reversible actuation of the microstructures into and out of the nutrient layer, and serves as a highly precise 'on/off' switch for chemical reactions. We apply this design to trigger organic, inorganic and biochemical reactions that undergo reversible, repeatable cycles synchronized with the motion of the microstructures and the driving external chemical stimulus. By exploiting a continuous feedback loop between various exothermic catalytic reactions in the nutrient layer and the mechanical action of the temperature-responsive gel, we then create exemplary autonomous, self-sustained homeostatic systems that maintain a user-defined parameter--temperature--in a narrow range. The experimental results are validated using computational modelling that qualitatively captures the essential features of the self-regulating behaviour and provides additional criteria for the optimization of the homeostatic function, subsequently confirmed experimentally. This design is highly customizable owing to the broad choice of chemistries, tunable mechanics and its physical simplicity, and may lead to a variety of applications in autonomous systems with chemo-mechano-chemical transduction at their core.     

西司他丁关键中间体的合成研究进展

 S-(+)2, 2-二甲基环丙烷甲酰胺是合成医药和农药的重要中间体,其合成方法主要分为化学合成法和生物催化法.综述了国内外2, 2-二甲基环丙烷甲酰胺的合成及拆分方法,并对各种合成方法进行分析对比,其中生物催化合成技术因具有高选择性、高催化效率和环境友好等优点而日益受到重视.生物催化合成法克服了化学合成工艺的缺陷,符合原子经济和可持续发展,具有广阔的发展前景.     

酶催化1-O-甘氨酰-3-O-十四烷酰化甘油的合成

甘油酯型氨基酸是一类新型的酯化氨基酸表面活性剂。酶法在选择性酯化合成氨基酸各类生物表面活性剂方面被证实具有意想不到的效果。文章介绍了以甘氨酸、甘油和十四烷酸为原料,对酶催化甘油单酯化合成1-O-甘氨酰-3-O-十四烷酰化甘油进行了探索。重点考察了No-vozyme435和Lipozyme IM的催化效果及特点,对反应时间、底物配比等影响因素进行了优化。     

苯乙酮合成方法的改进

对有机化学实验中“苯乙酮的合成”实验方法进行了改进,改进后的实验条件为:乙酸乙酯取代苯作溶剂;改变加料顺序、催化剂的加入量;降低反应温度,提高了苯乙酮的收率。     

苯偶酰的无溶剂催化反应合成及结构研究

采用FeC13.6H2O为催化剂,在无溶剂条件下,通过催化反应氧化苯偶姻合成苯偶酰。用红外光谱(IR)、元素分析、质谱和核磁共振谱(NMR)等手段对产物进行了表征和分析。结果表明,该方法与传统的溶液法相比较,具有无有机溶剂污染、反应速度快、反应产物易于分离、产率高和后处理简单等优点。