查询词典 disubstituted

The dependence of the characteristic ratio and the first interaction energy of PDMS is numerically calculated by analyzed the results of various models, we found that it is rather necessary to consider the structure of disubstituted groups if the polymers of rotational-isomeric-state model are calculated.

对PDMS链特征比与一级相互作用能的关系作了数值计算，通过对各种模型计算结果的分析，发现如果取旋转异构态模型进行计算，考虑侧基的结构是十分必要的。

A type of chiral molecular tweezers has been designed and synthesized by using diphenic acid as spacer and chiral unsymmetrically disubstituted urea as arm for the first time.

近年来，利用合成的人工受体与适当底物间的分子识别以建立仿生仿酶模型的研究，已成为生物有机化学和超分子化学前沿领域之一lL】。2 J。

The first part of this dissertation described a new effective method for asymmetric synthesis of,α,α-disubstituted amino acids from the asymmetric Strecker reaction products of aldehydes.

在本论文的第一部分，我们开发了一条以醛为原料，以不对称Strecker反应和不对称烷基化为关键步骤的合成α，α双取代氨基酸的有效方法，并对其立体选择性结果进行了机理探讨。

In the forth part of the dissertation, based on the mechanism of classical Strecker reaction,we developeda new method for the asymmetric synthesis of the α,α-disubstituted amino acid, and applied it to theasymmetric synthesis of-αM4CPG, compound 11a and 11b.

在本论文的第四部分，我们从深入分析经典的Strecker反应入手，发展了一条新的以酮为原料出发的立体选择性地合成α，α-双取代的光学纯的氨基酸的方法，并且利用该方法立体选择性地合成了化合物-αM4CPG，11a和11b。

In the third part of this dissertation, based on the leading compound ACPD, we design and asymmetric syhthesized two analogues: 56 and 57 by using Seebach's self- regeneration strategy to synthesize α,α-disubstituted amino acid as the key step.

论文的第二部分，我们利用我们所开发的合成α，α双取代氨基酸的方法，以对甲基苯甲醛为原料，经过分子内付克烷基化、氧化银氧化和氢化等16步反应，完成了代谢型谷氨酸受体拮抗剂-AIDA的不对称合成。

The reaction products between disubstituted phosphinosilane and alkynes were those eliminating SiMe3 after addition rather than those via normal addition.

二取代膦基硅烷和炔类化合物之间的反应不是一般的加成产物，而是加成后SiMe3被H消去的产物。

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 disubstituted ureas and the catalyst could be separated by addition of water and the catalyst could be reused without deactivation.

新型高效的菲咯啉钯-离子液体含氮化合物羰化催化剂体系，以苯胺为反应物时该体系的转化频率可以达到6000mol/mol/h；氢氧化铯-离子液体催化剂体系，可以在不加入化学计量脱水剂的条件下活化二氧化碳与脂肪族胺反应得到二取代脲，反应结束后可以通过加入水实现产品和催化剂体系的分离，催化剂体系可以重复使用。

Disubstituted 2-isoxazolines were oxidized to corresponding isoxazoles by NO in dichloromethane.

3、3，5-二取代的-2-异恶唑啉在NO作用下可以发生芳环化反应，生成对应的2-异恶唑化合物。

for preparing n-boc or n-cbz derivatives of chiral alpha,alpha'-disubstituted pyrrolidines containing olefinic bond and acetylene bond

一种制备含烯键和炔键取代基的手性α，α'-二取代吡咯烷的n-boc或n-cbz衍生物的方法

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。