降冰片烯的合成研究进展

Synthesis of norbornene

目前,降冰片烯合成方面的研究报道多为专利且年代跨度大,缺乏较为系统的综述。本文首先介绍了由(双)环戊二烯与乙烯合成降冰片烯的Diels-Alder反应机理,针对乙烯反应活性不足所采取的高压及高温两类补偿措施分别加以评述,并列举了其反应热及常见副反应等。结合高温高压及反应放热量大等特点,系统阐述了相关动力学研究方面的进展情况,为调控反应进程提供参考,以确保安全生产。本文还回顾了降冰片烯合成技术的发展过程,对比了现有液相工艺和气相工艺的优缺点,虽然气相工艺可以有效遏制副反应的发生,但由于气相工艺产量较低,目前实际生产中大多采用液相反应工艺,如何通过设计特殊结构的反应器以提高其混合效果是未来研究的关键所在。

Despite a large number of patents and scientific papers about norbornene synthesis in the last 70 years,a systematic review is lacking. Firstly,the synthesis of norbornene through the Diels-Alder reaction of （di）cyclopentadiene with ethylene is introduced,and the processes of elevated temperature and pressure to enhance the reactivity of ethylene are commented. Reaction heat and side reactions are listed. According to the characteristics of norbornene synthesis of high pressure/temperature and immense amount of reaction heat release,reaction kinetics which provides reference to controlling the degree of reaction is summarized for the safety of production technology. Moreover,the development of synthesis processes is reviewed,and the advantages and disadvantages of liquid phase process and gas phase process are compared. The gas phase processes could reduce side reactions,but low yield limits its wide use. At present,the liquid phase process is still a mainstream technology for synthesis of norbornene. At last,the design of reactors with special structure to enhance mixing of reaction process could be a key issue of future study.