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第25讲-C-13和2D NMR–亲电芳香取代Lecture 25 - C-13 and 2D NMR – Electrophilic Aromatic Substitution |
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| 课程网址: | http://videolectures.net/yalespan125bs2011_mcbride_lec25/ |
| 主讲教师: | J. Michael McBride |
| 开课单位: | 耶鲁大学 |
| 开课时间: | 2014-08-19 |
| 课程语种: | 英语 |
| 中文简介: |  |
| 课程简介: | Proton decoupling simplifies C-13 NMR spectra. Dilute double labeling with C-13 confirmed the complex rearrangement scheme in steroid biosynthesis. Two-dimensional NMR yields correlations between NMR signals that underlie structural determination of proteins and identification of the mechanism of a rapid carbocation rearrangement. Substitution of an electrophile for a proton on an aromatic ring proceeds by a two-step association-dissociation mechanism involving a cyclohexadienyl cation intermediate. The relative rates of forming various products from substituted benzenes correlates with the substituents' influences on the stability of the various cyclohexadienyl cation intermediates. The spectrum of electrophile reactivities is very broad. Important contributions for activating electrophiles were made by Friedel and Crafts working in Paris. |
| 关 键 词: | 质子去耦; 二维核磁共振; 亲电试剂 |
| 课程来源: | 视频讲座网 |
| 数据采集: | 2021-11-19：zkj |
| 最后编审: | 2021-11-19：zkj |
| 阅读次数: | 61 |