微波有机合成反应的新进展

综述了近来微波辐射技术在有机合成应用中的新进展。着重介绍了微波有机合 成反应技术及其在重要有机合成反应中的应用。     

The microwave-to-flow paradigm: translating high-temperature batch microwave chemistry to scalable continuous-flow processes

The popularity of dedicated microwave reactors in many academic and industrial laboratories has produced a plethora of synthetic protocols that are based on this enabling technology. In the majority of examples, transformations that require several hours when performed using conventional heating under reflux conditions reach completion in a few minutes or even seconds in sealed-vessel, autoclave-type, microwave reactors. However, one severe drawback of microwave chemistry is the difficulty in scaling this technology to a production-scale level. This Concept article demonstrates that this limitation can be overcome by translating batch microwave chemistry to scalable continuous-flow processes. For this purpose, conventionally heated micro- or mesofluidic flow devices fitted with a back-pressure regulator are employed, in which the high temperatures and pressures attainable in a sealed-vessel microwave chemistry batch experiment can be mimicked.     

有机微波化学研究进展

本文综述了近几年来微波技术在有机合成方面的研究和应用进展。初步探讨了微波催化有机反应的作用机理, 并展望了有机微波化学的发展前景。     

A novel method for the synthesis of polysubstituted diaminobenzonitrile derivatives using controlled microwave heating

A novel, simple and efficient method for the synthesis of polysubstituted diaminobenzonitriles has been developed that involves reaction of 1,1,3-tricyano-2-aminopropionitrile with nitroolefins under controlled microwave irradiation conditions.     

Synthesis of functionalized 1,3-thiazine libraries combining solid-phase synthesis and post-cleavage modification methods

The solid-phase synthesis of diverse sets of 1,3-thiazine-5-carboxylates on Wang resin is described. Acetoacetylation, followed by Knoevenagel condensation and an acid-promoted ring-closure reaction with thioureas furnished polymer-bound 1,3-thiazines. As an alternative to transesterification, a de-novo synthesis of beta-keto esters, starting from polymer-bound malonic acid through reaction with acyl imidazoles, was applied to increase the diversity. To reduce contamination, an on-bead purification of resin-bound 1,3-thiazines that makes use of differences in the reactivity of ester bonds toward alkoxides is reported. A final four-step post-cleavage modification of thiazine-5-carboxylates, derived by TFA cleavage from the Wang linker, leads to esters or amides. Twenty 1,3-thiazines were obtained in yields of up to 61 % over either 9 or 13 steps.     

Platform synthesis: A useful strategy for rapid and systematic generation of molecular diversity

Emergence of library-based approaches have changed the way of developing new functional molecules in materials science and pharmaceutical science. Therefore, reliable methods for rapid and systematic generation of functional molecules are highly called for in this field. We herein describe our concept of "platform synthesis" as a useful strategy for generating molecular diversity. This simple yet powerful strategy realizes the synthesis of a number of interesting multifunctional molecules, such as multisubstituted olefins, in a programmable and diversity-oriented format. As well as applications to the synthesis of pharmaceutically important molecules, such as tamoxifen and CDP840, applications to materials science, which have led to the discovery of interesting fluorescent materials and properties, are also described.     

微波辐射下有效合成缩氨基硫脲类化合物

将肼基二硫代甲酸甲酯与相应的醛或酮在微波辐射下,经2~3.5m in反应得到化合物3-二取代甲(乙)撑肼基二硫代甲酸甲酯1,收率90~96%,然后将化合物1与胺在微波辐射下,经35~45m in反应得到目标化合物2~4,收率68~90%。微波辐射法比常规法显著的缩短了反应时间,提高了收率。共计合成目标化合物19个。以上化合物均经过熔点测定、质谱、红外光谱、核磁共振氢谱对其结构进行确证。     

无溶剂微波辅助合成醚类化合物的工艺探讨

与传统加热方法相比,通过体系内部分子运动摩擦产热的微波辐射方法可催化化学反应,缩短反应时间,提高转化率和收率.传统的加热方法需要数十小时,甚至几天的反应.     

Continuous flow techniques in organic synthesis

As part of the dramatic changes associated with the need for preparing compound libraries in pharmaceutical and agrochemical research laboratories, the search for new technologies that allow automation of synthetic processes has become one of the main topics. Despite this strong trend for automation high-throughput chemistry is still carried out in batches, whereas flow-through processes are rather restricted to production processes. This is far from understandable because the main advantages of that approach are facile automation, reproducibility, safety, and process reliability, because constant reaction parameters can be assured. Indeed, methods and technologies are missing that allow rapid transfer from the research level to process development without time-consuming adaptation and optimization of methods from the laboratory scale to production plant scale. Continuous-flow processes are considered as a universal lever to overcome these restrictions and, only recently, joint efforts between synthetic and polymer chemists and chemical engineers have resulted in the first continuous-flow devices and microreactors; these allow rapid preparation of compounds with minimum workup. Many of these approaches use immobilized reagents and catalysts, which are embedded in a structured flow-through reactor. It is generally accepted, that for achieving best reaction and kinetic parameters for convective-flow processes monolithic materials are ideally suited as solid phases or polymer supports. In addition, immobilization techniques have to be developed that allow facile regeneration of the active species in the reactor.     

Combinatorial Methods,Automated Synthesis and High‐Throughput Screening in Polymer Research: Past and Present

Combinatorial techniques, parallel experimentation and high‐throughput methods represent a very promising approach in order to speed up the preparation and investigation of new polymeric materials: a large variety of parameters can be screened simultaneously resulting in new structure/property relationships. The field of polymer research seems to be perfectly suited for parallel and combinatorial methods due to the fact that many parameters can be varied during synthesis, processing, blending as well as compounding. In addition, numerous important parameters have to be investigated, such as molecular weight, polydispersity, viscosity, hardness, stiffness and other application‐specific properties. A number of corresponding high‐throughput techniques have been developed in the last few years and their introduction into the commercial market further boosted the development. These combinatorial approaches can reduce the time‐to‐market for new polymeric materials drastically compared to traditional approaches and allow a much more detailed understanding of polymers from the macroscopic to the nanoscopic scale. Here we provide an overview of the present status of combinatorial and parallel polymer synthesis and high‐throughput screening.

     

固相有机合成研究进展

组合化学技术给固相有机合成带来了新的发展契机,同时也提出了新的发展要求。目前这一研究领域发展迅速,应用范围不断扩大,技术日臻完善。本文综述了近期固相有机合成研究方面的最新进展。     

应用微波辐射技术一步合成4－芳基－1，4－二氢吡啶衍生物

以芳醛、乙酰乙酸乙酯、醋酸铵为原料在无溶剂条件下应用微波技术合成了4 －芳基－2，6－二甲基－3－5－二乙氧羰基－1，4－二氢吡啶，该反应的2－5min 内完成，产率73％－99％。     

Microwave-assisted synthesis of colloidal inorganic nanocrystals

Colloidal inorganic nanocrystals stand out as an important class of advanced nanomaterials owing to the flexibility with which their physical-chemical properties can be controlled through size, shape, and compositional engineering in the synthesis stage and the versatility with which they can be implemented into technological applications in fields as diverse as optoelectronics, energy conversion/production, catalysis, and biomedicine. The use of microwave irradiation as a non-classical energy source has become increasingly popular in the preparation of nanocrystals (which generally involves complex and time-consuming processing of molecular precursors in the presence of solvents, ligands and/or surfactants at elevated temperatures). Similar to its now widespread use in organic chemistry, the efficiency of "microwave flash heating" in dramatically reducing overall processing times is one of the main advantages associated with this technique. This Review illustrates microwave-assisted methods that have been developed to synthesize colloidal inorganic nanocrystals and critically evaluates the specific roles that microwave irradiation may play in the formation of these nanomaterials.     

微波技术在组合化学合成反应中的应用研究进展

本文综述了微波技术在组合化学的无溶剂平行合成反应、固相合成反应和液相合成反应中的应用，并根据研究的结果，提出微波技术在组合化学中进一步应用的前景。参考文献27篇。