查询词典 trisubstituted

We have studied the transition metal complexes catalyzed sequential cross coupling reactions of these new difunctional group reagents with electrophiles and nucleophiles, respectively; developed some convenient and practical new methods for the stereoselective synthesis of disubstituted alkenes, trisubstituted alkenes, conjugated dienes containing heteroatom, conjugated enyne containing heteroatom etc., enriching methodologies for organic synthesis.

继而研究了这些新型双官能试剂在过渡金属配合物催化下分别与亲电试剂、亲核试剂的顺序交叉偶联反应，为双取代烯烃、三取代烯烃、杂原子取代的共轭二烯烃、杂原子取代的共轭烯炔烃等的立体选择合成提供了方便实用的新方法，丰富了烯烃立体选择合成的方法学。

In this thesis, we developed a new method to construct 2, 3, 6-trisubstituted piperidines using enantiopure -amino acid derivatives as the starting material and applied them to the synthesis of some piperidine alkaloids which showed interesting physiological activities.

本论文中，我们从非手性原料出发，通过手性胺对、(-不饱和酯的Michael加成来获得光学纯的-氨基酸酯，发展了一种构建2、3、6-三取代哌啶环的方法，并利用这种方法合成了一些具有重要生理活性的生物碱类天然产物。

The positive charge transport properties of monosubstituted triphenylene are better than those of disubstituted and trisubstituted triphenylenes obviously.

在苯并菲上单取代的分子明显比其双取代、三取代的分子正电荷传输性质好。

Methodologies for stereoselective synthesis of alkenes are of great interest in synthetic organic chemistry since many biologically active compounds occuring in nature possess the structural skeleton of disubstituted or trisubstituted alkenes.

烯烃的立体选择合成方法学研究是有机合成化学中的重要课题，因为许多重要的天然产物中均含有双取代或三取代烯烃的结构单元。

The mole fractions of unsubstituted, monosubstituted, disubstituted, and trisubstituted anhydroglucose units are in very good agreement with Spurlin model during the determined range.

在测量的范围内，未取代、一取代、二取代和三取代无水葡萄糖单元的摩尔分数分布和Spurlin模型非常吻合。

Synthesis of 7, 3', 5'-Trisubstituted Flavanones and Flavonols

篇名 7， 3'， 5'-三取代黄烷酮和黄酮醇类化合物的合成

The second part, we have developed a convenient and highly-regioselective approach to synthesis of trisubstituted iodofurans.

第二部分，我们发展出一个便利且具有高度位向选择性的方法来制备三取代碘化呋喃，由高炔丙基醇可以顺利的得到2，4，5-三取代碘化呋喃。

A series of tri-radicals with heterospin center of 1,3,5- trisubstituted benzee as feeomagnetic coupling unit has been studied by using quantum chemical DFT UB3LYP method.

采用量子化学DFT UB3LYP方法，在6-31G基组水平上讨论了以1，3，5-苯为铁磁耦合单元的异自旋中心三自由基体系。

Under ultrasonic radiation,four single substituted arylboronic acid were synthesized through the reaction of trisubstituted borate and halogenated hydrocarbon induced by iodine.

在超声条件下，以碘为催化剂，利用硼酸酯与卤代芳烃、金属镁粉合成了4种单取代芳基硼酸。

Molybdophopsphoric Acid Catalysis in the Oxidative Cleavage of Olefins by the Hydrogen Peroxide Oxidative cleavage of the double bond could be catalyzed by H_3PMo_(12)O_(40) using H_2O_2 as oxidant, various trisubstituted olefins were oxidized to aldehydes or ketones in high yields. The system was not satisfied for electron-deficient olefins such as trans-(2-nitrovinyl) benzol or chalcone. The reaction of aliphatic olefins did not occur under the same conditions.

二、磷钼酸催化过氧化氢对烯烃的氧化断裂反应用过氧化氢(30％)作为氧化剂，磷钼酸可以催化氧化碳碳双键的断裂反应，三取代的烯烃被氧化生成醛或酮，产率较高；此体系对于缺电子烯烃如查尔酮，不饱和硝基化合物的断裂反应效果较差，脂肪族烯烃在此体系下的氧化并不发生。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。