共查询到20条相似文献,搜索用时 109 毫秒
1.
2.
3.
4.
5.
6.
7.
将甲苯液相均相选择性催化氧化反应的催化剂分为:过渡金属盐、杂多化合物、过渡金属配合物、非金属化合物、复合催化剂等,对反应条件、结果和机理进行了总结。杂多化合物或金属卟啉参与反应时,反应条件较温和,对苯甲醛和苯甲醇的选择性高。复合催化剂通常表现出更好的催化性能,而且,当催化剂由非金属催化剂和金属催化剂组成时,对产物的选择性主要取决于金属催化剂部分。此外,以甲苯侧链的氧化为重点阐述了反应机理,指出开发更高效的复合催化剂和粗甲苯的氧化工艺是今后的发展重要方向。 相似文献
8.
9.
本文综术了杂多化合物作为酸催化剂,催化烷基化和去烷基化反应、缩聚反应、水合和失水、酯化和醚化反应;以及作为氧化催化剂,在烯烃、芳烃、酚的氧化和环氧化反应中的应用。表面杂多化合物作为催化剂在合成精细化学中有广泛的应用价值。 相似文献
10.
11.
12.
13.
喹唑啉类化合物具有良好的生物活性,其合成新方法也层出不穷。就近几年来有关喹唑啉类化合物的合成新方法进行了综述,重点介绍了微波法、闭环法、一锅法合成喹唑啉类化合物。 相似文献
14.
15.
卟啉及金属卟啉类化合物的研究进展及展望 总被引:2,自引:0,他引:2
系统地介绍了卟啉及金属卟啉类化合物在分子结构设计、合成方法和应用研究方面的最新进展及展望.基于大量文献及本课题组的研究工作,特别指出了这类化合物在合成方法上的改进以及在仿生催化烃类选择氧化方法的研究进展. 相似文献
16.
17.
有机化合物合成路线的设计方法一般从剖析有机物的化学结构入手,然后考虑其合成方法。有机合成路线设计方法一般有四种,重点介绍了倒推法来设计有机化合物的合成路线,并列举了若干有机化合物设计合成路线的成功例子。 相似文献
18.
酚类化合物的提取是实现煤焦油高附加值利用的有效途径之一,掌握煤焦油中酚类化合物的分布情况、结构特点有助于高效分离方法的开发。针对煤焦油中粗酚的提取及精制,本文综述了碱液抽提法、溶剂萃取法和新型分离方法3类粗酚提取方法的研究现状,介绍了粗酚精制的研究进展,并讨论了不同粗酚提取、精制方法之间的优势与不足。系统阐述了光谱法、色谱法及核磁共振法3大类酚类化合物组成结构鉴定方法。探讨了该领域技术的发展趋势,认为酚类的分析鉴定需将多种先进手段结合,多层次、全方位地分析其组成及结构;粗酚的提取可以加快环保高效萃取剂的优选,推动新型萃取法的应用进度;粗酚精制在重点开发间、对甲酚及混合二甲酚高效提纯工艺的同时,加强高级酚提取的研究力度。 相似文献
19.
20.
A knowledge of the volatile components present in an oil sample can provide important information relative to supercritical
fluid extraction (SFE) process design, the current oxidative state of the oil, as well as the concentration and presence of
important flavor volatiles in the oil. Volatile compounds from supercritical fluid-extracted oils were analyzed by headspace
gas chromatography (GC) methods to determine if there were differences in the volatile profiles when two different methods
of desorption were used. Canola, corn, soybean and sunflower seeds were extracted with supercritical carbon dioxide at 8000
psi and 50°C. Tenax porous polymer traps, attached at the exhaust port of the SFE apparatus, were utilized to collect the
volatile components during the extractions. The volatile compounds on the Tenax trap were desorbed onto a GC column by both
thermal and supercritical fluid techniques. Desorption temperature for the thermal method was 150°C, while conditions for
the SFE technique were 50°C and 2000 psi. The lower-boiling volatiles from each oilseed were greater when desorbed by thermal
means from the Tenax than by SFE; however, SFE desorbed the highermolecular weight compounds that were not removed by the
thermal desorption method. Hexanal tended to be desorbed in comparable amounts by both methods. The SFE-based desorption technique
provides a unique analysis method for the determination of both volatile and semivolatile compounds, as well as executing
desorption under nonoxidative, low-temperature conditions that do not contribute to the degradation of lipid components. 相似文献