顺式-反式
- 与 顺式-反式 相关的网络例句 [注:此内容来源于网络,仅供参考]
-
The reaction of cyclic b-keto esters with CF3CO2ZnCH2I provides the corresponding ring-expanded products with the advantage of mild condition in moderate to good yields. A simple and efficient procedure has been developed for a variety of 1,3-diketones converted into the corresponding 1,4-diketones and trans-1,2-disubstituted cyclopropanols in high yields. In conclusion, this new type of organozinc reagents has been developed for many useful reaction in organic synthesis.
利用有机锌试剂所具有的双重特性,在新型的Baylis-Hillman反应中,可以直接与炔基酮和醛反应一锅制得多官能团的三取代的顺式烯;在b-酮酯化合物的扩环反应中,取得了重要进展,得到了增加一个碳的扩环产物,&一步法&合成,反应条件温和、环境友好;在1,3-二酮分子中成功地插入1个碳,合成出1,4-二酮和环丙醇,为现代有机合成提供了新的合成方法,具有良好的应用前景。
-
Keywords: Organozinc reagents; cis-Addition Products; Ring-expansion; Chain-extension
中文关键词:有机锌试剂;环氧的顺式开环;酮酯的扩环;碳链增长
-
Organozinc reagents; cis-Addition Products; Ring-expansion; Chain-extension
中文主题词:有机锌试剂;环氧的顺式开环;酮酯的扩环;碳链增长
-
The structure analysis indicates that the reverse symmetry ligand H4LB molecules are linked into a 2D supermolecular network by two types of hydrogen bonds. One type occurs between the oxalamide oxygen group and the phenol hydroxyl qroup of the nearest molecule with d=2.906(2) and ∠O-H…O=151.8°. The other type is between the oxalamide nitrogen group and the oxalamide oxygen group of anther molecule with d=2.849(2),∠N-H…O=158.7°.
晶体结构研究表明配体H4L为顺式桥联分子,晶体中存在两种氢键,一种是草酰胺基团的O原子与苯环上的酚羟基形成O-H…O氢键[d=2.906(2),∠O-H…O=151.8°];另一种是草酰胺基团的氨基与相邻草酰胺基上的O原子形成N-H…O氢键[d=2.849(2),∠N-H…O=158.7°],通过上述两种氢键将化合物H4LB连接成二维网络结构。
-
FeSi nanoparticles were synthesized via thermal decomposition of iron pentacarbonyl in the solution of dioctyl ether, stabilizers oleic acid and oleylamine. The TEM images showed that FeSi nanoparticles had cubic shape, but it seemed that the composition was not uniform. According to the EDS results, the Fe:Si ratio of gray-uniform nanopaiticles was almost 1:1, and blacker FeSi nanoparticles contained more Fe atoms. Although FeSi didn't have uniform structure, it still could be proved that the incorporation of Fe and Si existed in a single nanoparticle. All possible structure, lattice, binding, morphology, surface condition would be discussed. These results indicated that perhaps FeSi2 was the main structure of the new products; however, due to incompletely combination and less synthesized time, it might still contain some part of Si and Fe structure. Besides, FeSi nanoparticles preserved the optical properties from Si atoms, but the PL intensity was much lower. The maxima PL peak appeared at 388 nm with the excitation at 300 nm. Their saturation magnetization, remanent magnetization and coercivity were measured by the SQUID, exhibiting their nearly superparamagnetic behavior.
利用热裂解系统可成功将研磨矽奈米粒子及五羰铁结合,制备出铁矽奈米粒子;从穿透式显微镜照片可知其粒子呈现立方体型态,但颜色深浅及组成不均,EDS结果则显示颜色均匀之粒子铁与矽之组成大致为1:1,颜色较深之粒子则含有较高量的铁元素;尽管组成比例并不统一,但单颗粒子同时含有矽与铁两种元素,初步说明铁矽奈米粒子之形成;进行多种结构与表面分析并探讨所有可能之键结、结构及表面元素后,推测铁矽奈米粒子可能以FeSi2之结构形成,并同时包含未重组完成的矽及铁之结构;利用PL分析得知铁矽奈米粒子确实保留矽之放光特性,并在300 nm激发光源下,於波长388 nm处有一最强放光特性峰,但整体发光效益不及研磨矽奈米粒子之结果;最后,利用超导量子干涉磁化仪量测其饱和磁化量、残留磁化量、与矫顽磁力,发现磁滞现象并不明显而几乎呈超顺磁性。
-
Erve growth factor combined with its receptor, activated Ras - MAP kinase , mitogen - activated protein kinase kinase is the important regulating factor that make IkB kinase, IKK, phosphated, IkB kinase make the IκBα:(the subunit of NF -κB ) phosphated, the phosphated IkBα degraded, and p65 - p50 heterodimer can be formed, then the heterodimer translocated to nucleus and combined with the promoter domain or other consensus sequence.
GF与其受体相结合,最后可以激活Ras-有丝分裂激活的蛋白激酶途径,有丝分裂激活的蛋白酶激酶(MEKK1)是IγB激酶发生磷酸化的重要调节因子,IKK使NF-κB的亚单位IKBα发生磷酸化,磷酸化的IKBα发生降解,而最后留下p65-p50二聚体,该二聚体然后转位到细胞核内与κB基因的增强子区域或与他的顺式作用序列结合。
-
From the starting material: propargyl alcohol, the building block was prepared easily by Jones oxidation, esterfication, bromination and selective trifluoromethylation.
第一部分:从丙炔醇出发,经过Jones氧化,甲酯化,顺式二溴化,再选择性地在酯基的β位实现三氟甲基化,合成了目标含氟砌块。
-
The chiralMn complexes, especially Jacobsenscatalyst, display high enantioselectivity for asymmetric epoxidation of conjugated cis-di-, tri-and some tetrasubstituted prochiral alkenes in the NaClO biphasic system, but the epoxidationreaction generally requires a long reaction time even in the presence of an axial ligand.
在NaClO两相体系中,手性Mn配合物,尤其是Jacobsen催化剂,对共轭顺式二取代、三取代和部分四取代烯烃的不对称环氧化具有高的对映选择性,然而即使存在轴向配体,环氧化反应也通常需要长的反应时间。
-
The chiralMn complexes, especially Jacobsen\'scatalyst, display high enantioselectivity for asymmetric epoxidation of conjugated cis-di-, tri-and some tetrasubstituted prochiral alkenes in the NaClO biphasic system, but the epoxidationreaction generally requires a long reaction time even in the presence of an axial ligand.
在NaClO两相体系中,手性Mn配合物,尤其是Jacobsen催化剂,对共轭顺式二取代、三取代和部分四取代烯烃的不对称环氧化具有高的对映选择性,然而即使存在轴向配体,环氧化反应也通常需要长的反应时间。
-
Methods Sixty patients with malignant pleural effusions were randomly assigned to small bore catheter thoracostomy closed drainage group or conventional pleural aspiration group.
方法将恶性胸腔积液患者随机分成两组,分别进行中心静脉导管闭式引流和常规胸腔穿刺,并均于胸腔内注入顺铂(cisplatin,DDP)和白介素-2(interleukin-2,IL-2)。
- 推荐网络例句
-
I didn't watch TV last night, because it .
昨晚我没有看电视,因为电视机坏了。
-
Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.
今年以来,在北京的很多小区里,电梯液晶电视被撤了下来。
-
I'm running my simile to an extreme.
我比喻得过头了。