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第17讲-炔烃；烯丙基中间体和二烯烃中的共轭Lecture 17 - Alkynes; Conjugation in Allylic Intermediates and Dienes |
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| 课程网址: | http://videolectures.net/yalespan125bs2011_mcbride_lec17/ |
| 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: | Because of their unusual acidity very strong base makes it possible to isomerize an internal acetylene to the less stable terminal isomer. Many chemical reactions may be understood in terms of localized bonds, but the special stability of conjugated systems requires considering delocalized orbitals or "resonance." Equilibrium constants, rates, and regiochemistry in systems involving allylic cations, anions, transition states, and free radicals demonstrate that allylic conjugation is worth about 13 kcal/mole. Regioselection in addition of DCl to 1,3-pentadiene reveals rapid collapse of an allylic ion pair. Allylic substitution of bromine can be favored over Br2 addition by using NBS to control Br2 concentration. Diene conjugation is worth much less than allylic conjugation. |
| 关 键 词: | 乙炔; 末端异构体; 共轭体系 |
| 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: | 70 |