The green and effective Baeyer-Villiger oxidation reaction of cyclohexanone for preparing e-caprolactone is of particular importance in the synthesis of new polymer materials. We have discussed here several mechanism ...The green and effective Baeyer-Villiger oxidation reaction of cyclohexanone for preparing e-caprolactone is of particular importance in the synthesis of new polymer materials. We have discussed here several mechanism types of Baeyer-Villiger oxidation of cyclohexanone with H2O2 in different reaction systems. Five main types have been addressed, i. e.： （1） the non-catalyzed reaction type, where the C=O of ketones is activated by H＋, which is electrolytically dissociated from H202 and H20, to improve the capability of C=O group for accepting the electron pairs; （2） the thermally activated radical reaction type, where the Criegee intermediate is produced via two steps of radical reaction with -OH attack, with much more hydroxyl radicals being excited in the presence of TS-1 zeolite; （3） the Bronsted acid catalysis reaction type, where both O-O moiety and C=O group could be activated by BriSnsted acid; （4） the solid Lewis acid catalyzed C=O of the substrate activation reaction type through enhancing the donor-acceptor interaction between the antibonding π＊c-o orbital of cyclohexanone and HOMO of Sn-containing zeolites; and （5） the solid Lewis acid catalyzed H202 to form Me-OOH oxidative species by converting the highest occupied molecular orbital （HOMO） of Ti-OOH into a singly occupied molecular orbital （SOMO）, making the O--O group highly electrophilic to attack the C--O of cyclohexanone during the Baeyer-Villiger oxidation process. In the end, we have also compared the different mechanisms and put forward our opinions on the development direction of catalytic materials aiming at eco-friendly Baeyer-Villiger oxidation of cyclohexanone in the years to come.展开更多
文摘目的建立一次性使用输液器中环己酮残留量的测定方法。方法利用模拟浸提法对输液器中的环己酮进行提取,采用气相色谱法进行测定。色谱柱为HP-INNOWAX Polyethylene Giycol长60 m,直径320.00μm,膜0.25μm;进样口温度200℃,检测器温度230℃,氢气流量30.0 m L/min,空气流量300.0 m L/min;氢火焰离子化检测器,载气为氮气;以水为溶剂,用顶空方式进样。结果环己酮质量浓度为4.165-133.300μg/m L时具有良好线性关系（r=1.000 0）;平均回收率为97.2%（n=9）,相对标准偏差为3.08%。结论顶空气相色谱法简单、准确,可用于一次性使用输液器中环己酮残留量的检测。
文摘The green and effective Baeyer-Villiger oxidation reaction of cyclohexanone for preparing e-caprolactone is of particular importance in the synthesis of new polymer materials. We have discussed here several mechanism types of Baeyer-Villiger oxidation of cyclohexanone with H2O2 in different reaction systems. Five main types have been addressed, i. e.： （1） the non-catalyzed reaction type, where the C=O of ketones is activated by H＋, which is electrolytically dissociated from H202 and H20, to improve the capability of C=O group for accepting the electron pairs; （2） the thermally activated radical reaction type, where the Criegee intermediate is produced via two steps of radical reaction with -OH attack, with much more hydroxyl radicals being excited in the presence of TS-1 zeolite; （3） the Bronsted acid catalysis reaction type, where both O-O moiety and C=O group could be activated by BriSnsted acid; （4） the solid Lewis acid catalyzed C=O of the substrate activation reaction type through enhancing the donor-acceptor interaction between the antibonding π＊c-o orbital of cyclohexanone and HOMO of Sn-containing zeolites; and （5） the solid Lewis acid catalyzed H202 to form Me-OOH oxidative species by converting the highest occupied molecular orbital （HOMO） of Ti-OOH into a singly occupied molecular orbital （SOMO）, making the O--O group highly electrophilic to attack the C--O of cyclohexanone during the Baeyer-Villiger oxidation process. In the end, we have also compared the different mechanisms and put forward our opinions on the development direction of catalytic materials aiming at eco-friendly Baeyer-Villiger oxidation of cyclohexanone in the years to come.
