超临界二氧化碳介入的α-松油醇催化合成1,8-桉叶素  

Catalytic isomerization ofα-terpineol to 1,8-cineole in supercritical carbon dioxide

作　　者：洪燕珍[1] 王笛 李卓昱 徐亚南 王宏涛[1] 苏玉忠[1] 彭丽 李军[1] HONG Yanzhen;WANG Di;LI Zhuoyu;XU Yanan;WANG Hongtao;SU Yuzhong;PENG Li;LI Jun(College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,Fujian,China)

机构地区：[1]厦门大学化学化工学院,福建厦门361005

出　　处：《化工学报》2021年第7期3680-3685,共6页CIESC Journal

基　　金：厦门大学校长基金项目(20720180027)。

摘　　要：提出超临界二氧化碳介入α-松油醇异构合成1,8-桉叶素的方法,并采用二极管阵列检测器测量超临界二氧化碳下α-松油醇/环己烷体系的最大吸收波长研究二氧化碳加入量与极性的关系。考察了溶剂体系极性、溶剂量和二氧化碳压力对磷钨酸/聚离子液体(PW/PIL)催化剂催化α-松油醇异构合成1,8-桉叶素的影响,并探讨了超临界二氧化碳介质中,PW/PIL催化剂催化α-松油醇异构合成1,8-桉叶素可能的反应机理。开发了一种绿色高效的1,8-桉叶素合成工艺,当环己烷/α-松油醇的质量比10∶1,PW/PIL催化剂/α-松油醇的摩尔比0.0163∶1,CO2压力19.0 MPa,50℃反应8 h时,α-松油醇的转化率为89.3%,1,8-桉叶素的选择性为54.6%。研究表明,超临界二氧化碳起到共溶剂、膨胀溶剂、降低溶剂体系极性的三重作用,从而改善了催化剂的团聚现象,提高了1,8-桉叶素的选择性。This work proposes a method for supercritical carbon dioxide to interveneα-terpineol to synthesize 1,8-cineole.In addition,the diode-array detector was employed to measure the maximum absorption wavelength of theα-terpineol/cyclohexane mixture in supercritical carbon dioxide for analysis of the relationship between the amount of carbon dioxide and the polarity of the system.The catalytic isomerization was studied by considering the effects of polarity,solvent amount,and carbon dioxide pressure.The plausible mechanism for isomerization ofα-terpineol to 1,8-cineole by phosphotungstic acid/poly(ionic liquid)(PW/PIL)in supercritical carbon dioxide was proposed.This work offers a novel green and efficient supercritical technique for the synthesis of 1,8-cineole.In supercritical carbon dioxide,89.3%conversion ofα-terpineol and 54.6%selectivity to 1,8-cineole were obtained with the mass ratio of cyclohexane toα-terpineol 10∶1 and the molar ratio of PW/PIL catalyst toα-terpineol 0.0163∶1,at 19.0 MPa,50℃for 8 h.The results showed that supercritical carbon dioxide as co-solvent expanded the applied solvent as well as reducing the polarity of the system;therefore,the catalyst aggregation was alleviated obviously,and as a result the selectivity of 1,8-cineole was increased.

关 键 词：Α-松油醇 1 8-桉叶素 超临界二氧化碳 二极管阵列检测器 极性 

分 类 号：TQ032.4[化学工程]