查询词典 benzylic

The system exhibits favorable catalytic activity for the oxidation of benzylic and allylic alcohols, in spite of low activity observed for the oxidation of heterocyclic and aliphatic alcohols.

探讨了TEMPO-IL/CuCl催化体系的催化机理，铜离子是反应的活性中心。针对 TEMPO/CuCl 催化体系反应速度较慢的问题，研究了碱对 TEMPO/CuCl 体系的促进作用。

Various alcohols are tolerable under the present conditions including benzylic alcohols,allylic alcohols as well as simple aliphatic alcohols.

醇的范围非常广，二苯甲醇、1-苯乙醇、烯丙醇衍生物等含苄醇结构的地物能够以最高接近定量的产率得到产物。普通烷基醇如环己醇，甚至最简单的甲醇和乙醇也能顺利反应，产率中等。

C. In addition, they introduced a fluorosubstituted benzylic ester (CH 2 C 6 H 4 CH 2 CH 2 C 8 F 17 ) as a protecting group in solution-phase peptide synthesis to facilitate the purification of intermediates by fluorous-solid-phase extraction.

丙此外，他们推出了fluorosubstituted苄酯(丙6小时2楚楚242丙的CH8六17)为保护群液相肽合成纯化中间体的便利氟-固相萃取。

The novel complex (1) in which both benzylic nitrogens and heteroaromatic ones to the same metal ion with the rigid ligand imposed by the large heteroaromatic moiety first time was synthesized; a 2: 1 (ligand: metal ions) type complex which has steric resistance and strong thermochemical driving force was obtained. The crystal structures of characteristic ligand (LA4) and complexes (4, 7, 10), in which one cell includes two moieties: there exist minute difference in coordinated bonds and angles despite the same metal ions with the same ligand, were obtained. It shows that several stable conformation in one complex cell.

首次合成了含邻菲罗啉的具有较大刚性的四氮配体中四个氮原子全部与同一金属离子配位的配合物的晶体结构；得到了一个在空间上存在位阻作用的配体与金属离子2：1结构的晶体；解析了具有特色的一个配体（LA4）和三个配合物（4、7和10）的晶体结构，其中的配体与金属离子的配位作用显示出细微的差异，表明在同一金属配合物的晶胞中，可以同时存在着多个稳定的构象。

Various alcohols are tolerable under the present conditions including benzylic alcohols,allylic alcohols as well as simple aliphatic alcohols.

普通烷基醇如环己醇，甚至最简单的甲醇和乙醇也能顺利反应，产率中等。在这个反应中，磷钨酸能够顺利回收，并在此被用于催化反应，活性没有降低。

Bromination occur s selectively on the PMS methyl group, providing a reactive benzylic bromine functionality which is the key to Exxpro specialty elastomers′ vulcanization and modification versatility.

溴化反应选择性地发生在PMS的甲基基团上，提供活性苄基溴官能团，这也是Exxpro特种弹性体硫化和各种改性的关键。

Bromination occurs selectively on the PMS methyl group, providing a reactive benzylic bromine functionality which is the key to Exxpro specialty elastomers′ vulcanization and modification versatility.

溴化反应选择性地发生在PMS的甲基基团上，提供活性苄基溴官能团，这也是Exxpro特种弹性体硫化和各种改性的关键。

Electron-withdrawing groups decrease the reactivity of benzylic C - H whileelectron-releasing groups enhance its reactivity. This is consistent with the well-knownelectron-demanding character of the Rh-carbene complex.

从相对速率的数值〓可以看到，吸电子基使苯甲位反应活性降低，给电子基使苯甲位反应活性增大，这和Rh-卡宾的亲电性一致。

In this thesis, investigations focused on heteropoly acids-catalyzed C-C and C-N bond formation reactions and the synthesis of xanthenediones and acridinediones under thermal conditions are described.1.12-Phosphotungstic acid has been used as an efficient,eco-friendly,and air- and moisture-stable catalyst to promote the direct dehydrative substitution of the hydroxy group of benzylic and allylic alcohols with variousβ-dicarbonyl compounds.

本篇论文主要描述了杂多酸催化下的C-C和C-N键的生成，以及无溶剂直接加热下合成十氢氧杂蒽二酮和9-芳基十氢吖啶二酮。主要内容如下：1。在磷钨酸催化下，1，3-二羰基化合物与醇能够顺利偶合，脱除一分子的水，生成烷基化的1，3-二羰基化合物。反应在甲苯中进行时，二芳基甲醇能与各类1，3-二羰基化合物反应，成率很高；但对于1-苯乙醇，只能得到很低的产率。

Grasp the electron delocolization theory; be capable of judging the relative stability of allylic and benzylic free radicals and carbocations, know the relative stability of dienes and other multiple unsaturated hydrocarbons; grasp the characteristics for the nucleophilic substitution reactions of allyl halides and benzyl halides, and the addition reactions of conjugate dienes.

掌握电子非定域化理论；能够分析判断烯丙基、苄基自由基和正离子的稳定性和二烯及多重不饱和碳氢化合物的稳定性；掌握烯丙基、苄基卤代物的亲核取代反应特性和共轭二烯的加成反应。

Now, however, all children continue in "comprehensive" schools, and the eleven-plus determines which courses of study the child will follow.

然而现在，所有的孩子都要在综合学校继续学习，所以这次考试只是决定他们将要学习哪些课程。

Cultivatable land , and led to a general recognition that development must not be carried at the cost of agriculture .

城区的迅速扩大在很多情况下侵占了宝贵的可耕地，使人们普遍认识到发展不能以牺牲农业为代价。