查询词典 pinacol

Ultrasound, Expansive Graphite, Cinnamic Acid, Ethyl Alkylidene a- Cyanoacetate, Montmorillonite, Pinacol

超声波，膨胀石墨，肉桂酸，烷叉基氰乙酸乙酯，蒙脱土，片呐醇

The effects of CO2 initial pressure and temperature on the kinetics of pinacol rearrangement were studied.

实验结果表明：CO2的引入可以提高高温液态水中频那醇重排反应的速度及产物频那酮的收率。

And we have researched the pinacol coupling reactions in sunlight and ultrasound irradiation.

论文综述了片呐醇偶联反应的进展，在光照或超声辐射下进行了片呐醇的合成，全文共分为四章。

New methods for asymmetric synthesis of pinacol are reviewed, the catalytic effects and stereo- selectivity with various catalytic systems are discussed in this paper.

综述了近年来不同催化体系的不对称合成呐醇的方法，并总结了不同的催化效率和对映选择性的差异

In addition, it was found that the presence of protic agent such as water would lead to the increase of pinacol byproducts.

本文还根据循环伏安实验和合成实验结果简要地讨论了反应机理。

Progress in pinacol coupling of aldehydes and ketones using low valent titanium is reviewed in recent years.

由低价钛络合物诱发的片呐醇偶联反应，具有良好的化学选择性和立体选择性，近几年来又引起有机化学家们的极大兴趣与重视。

An environmentally benign method to accelerate the pinacol rearrangement in high temperature liquid water by the addition of CO2 was proposed.

引言频那醇重排反应是合成醛、酮的基本方法之一。

In Chapter Ⅱ, the pinacol-coupling reactions of carbonyl compounds promoted by dysprosium were described. The reaction of ketones and aldehydes promoted by Dy/n-BuBr were proceeded in anhydrous THF which gave pinacol in high yield.

第二章研究了金属镝促进下羰基化合物的还原偶联反应，醛、酮在无水THF中与Dy/n-BuBr反应，可高产率地得到频哪醇。

Expanding pinacol reductive coupling reaction into asymmetric one with both diastereoselectivity and enantioselectivity may lead to its application in synthesising medicaments and biologic active compounds with structure of vicinal diol. Asymmetric pinacol coupling reaction is also the most compact and effecient method in synthesizing chiral ligands or chiral auxiliary with C〓 symmetry.

将这一反应发展成为既有高度的非对映选择性，又有高度对映选择性的不对称偶联反应在合成许多含有手性邻二醇结构的药物或生物活性物质将有更重要的应用，同时不对称Piancol偶联反应也是合成C〓对称性的邻二醇多用途手性配体或手性助剂的最为简捷有效的方法。

Nevertheless, the yield of pinacol was also strongly affected by the steric environment surrounding the carbonyl group. The pinacol coupling of aromatic aldehydes has been achieved with high yields under such a condition. However, the diastereose-lectivities of pinacols were not satisfying. Unfortunately, the ketones and most aliphatic aldehydes appeared inert under the same reaction conditions.

然而， 呐偶合反应的产率受到羰基周围环境的立体位阻影响较大，在此条件下，锌粉能有效地促进芳香族醛类化合物进行水相呐偶合反应，得到的呐醇产率高，但非对映异构体选择性差，而脂肪族醛类化合物得到的呐醇产率较低，在同样的条件下，酮类化合物不能顺利进行呐偶合反应。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。