第27讲-三苯基甲基和羰基化学导论Lecture 27 - Triphenylmethyl and an Introduction to Carbonyl Chemistry |
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课程网址: | http://videolectures.net/yalespan125bs2011_mcbride_lec27/ |
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: | 对他的“六苯基乙烷”及其反应性的艰苦研究使冈伯格确信,他已经制备了第一种三价碳化合物——三苯基甲基自由基,这一发现标志着美国基础有机化学的出现。同位素标记可以确定质子化环丙烷是否在Friedel-Crafts烷基化反应中起作用。醛类和酮类的C-13核磁共振谱显示了如何根据经验确定特征化学位移。羰基在热力学上是稳定的,但在动力学上是反应的。其酸和碱催化反应通常涉及α-质子损失以形成烯醇或烯醇酯中间体。羧酸表现出四种根本不同的反应模式。缩醛的酸催化水解说明了涉及羰基的多步骤反应机理。 |
课程简介: | Painstaking studies of his "hexaphenylethane" and its reactivity convinced Gomberg that he had prepared the first trivalent carbon compound, triphenylmethyl radical, the discovery of which marked the emergence of fundamental organic chemistry in America. Isotopic labeling could decide whether protonated cyclopropane plays a role in Friedel-Crafts alkylation. C-13 NMR spectra of aldehydes and ketones show how characteristic chemical shifts are established empirically. The carbonyl group is thermodynamically stable but kinetically reactive. Its acid- and base-catalyzed reactions often involve loss of α-proton to form an enol or enolate intermediate. Carboxylic acids display four fundamentally different reaction patterns. Acid-catalyzed hydrolysis of acetals illustrates a multistep reaction mechanism involving the carbonyl group. |
关 键 词: | 三苯基甲基自由基; 羰基; 多步骤反应机理 |
课程来源: | 视频讲座网 |
数据采集: | 2021-11-18:zkj |
最后编审: | 2021-11-18:zkj |
阅读次数: | 52 |