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第35讲-酰基插入和α-反应性Lecture 35 - Acyl Insertions and α-Reactivity |
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| 课程网址: | http://videolectures.net/yalespan125bs2011_mcbride_lec35/ |
| 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: | When a nucleophilic atom bearing a good leaving group attacks a carbonyl group, an adjacent Rgroup can migrate to the new atom, inserting it into the R-acyl bond. This mechanism can insert O, NH, or CH2 groups into the acyl bond with informative stereospecificity in the case of the Beckmann rearrangement of oximes. Although the migrating groups are formally anionic, relative migratory aptitudes show that they give up electron density during rearrangement. Acid dissociation of protons a to a carbonyl group to form enolates, and the ease of forming enols, gives α-carbons nucleophilic reactivity under both basic and acidic conditions. This explains H/D exchange and racemization as well as halogenation and alkylation of α-carbons. |
| 关 键 词: | 酰基键; 亲核反应性; 亲核原子 |
| 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: | 54 |