西北农林科技大学：《有机化学 Organic chemistry》课程教学课件（2009）Chapter 09 Aromatic chemistry

Qs As 10s04 OH 2 NaHSO3,H2O OH KMnO4 cold,diluted OH OH Stereoselectivity Syn-addition

College Qs ＆ As of Science KMnO4 1 OsO4 2 NaHSO3，H2O cold,diluted OH OH OH OH Stereoselectivity Syn-addition

Section I -Aromatic chemistry

College of Science 西北农林科技大学理学院 Email: wangjr07@163.com Section I Aromatic chemistry

Section I 林 College Aromatic chemistry Aromaticity and reactivity ●Huckel rule Preparation and properties of Ar compounds Electrophilic substitutions Effects of substituents on electrophilic substitutions of substituted benzenes(E.S.) Synthesis of mono-,di-and tri-substituted benzenes Other reactions: .Oxidation and reduction

College of Science Section I Aromatic chemistry „Aromaticity and reactivity zHückel rule „Preparation and properties of Ar compounds „Electrophilic substitutions „Effects of substituents on electrophilic substitutions of substituted benzenes(E.S.) „Synthesis of mono-, di- and tri-substituted benzenes „Other reactions: zOxidation and reduction

I1 Aromaticity and Reactivity AdGif UNREGIST

College of Science I1 Aromaticity and Reactivity

I1 Aromaticity and Reactivity ■1 结构特征 ●6个SP2杂化碳原子 ●6个P轨道对成轴相互平行 ●闭合的共轭体系（环状π电子流）cyclic p system AdGif-UNREGISTERED ●平面结构，键角为1200 Planar ●高度离域（无单双键之分） High delocalized 芳香性

College of Science I1 Aromaticity and Reactivity „1 结构特征 z 6 个SP2杂化碳原子 z 6 个 P轨道对成轴相互平行 z闭合的共轭体系 (环状 π电子流) cyclic p system z平面结构 ,键角为1200 Planar z高度离域 (无单双键之分 ) High delocalized 芳香性

I1 Aromaticity and Reactivity 140pm 146pm 140pm 140pm 微微米 140pm 134pm 140pm140pm 芳香性

College of Science I1 Aromaticity and Reactivity 140 pm 140 pm 140 pm 140 pm 140 pm 140 pm 146 pm 134 pm 微微米 芳香性

The conjugated system in the benzene ring results in the formation of a continuous -cloud,above and below the plane of the ring. An electrostatic potential map of benzene showing enhanced electron density above and below the ring plane

College of Science

I1 Aromaticity and Reactivity Each carbon contributes a p orbital Six p orbitals overlap to give cyclic p system; Six p electrons delocalized throughout p system High electron density above and below plane of ring

College of Science I1 Aromaticity and Reactivity „Each carbon contributes a Each carbon contributes a p orbital orbital „Six p orbitals orbitals overlap to give overlap to give cyclic p system ; „Six p electrons electrons delocalized delocalized throughout throughout p system „High electron density High electron density above and below plane of above and below plane of ring

I1 Aromaticity and Reactivity ■2.反应性 ●不易加成（苯环骨架不断开） ●发生取代（亲电取代E.S) ●侧链反应 ■3.芳香性化合物结构特征 >大的不饱和度(2≥4)2=？ >(环状)平面分子 >易进行亲电取代反应 芳香性

College of Science I1 Aromaticity and Reactivity „2. 反应性 z不易加成 (苯环骨架不断开 ) z发生取代 (亲电取代 E.S) z侧链反应 „3. 芳香性化合物结构特征 ¾大的不饱和度 ( Ω ≧4) Ω=? ¾ (环状 )平面分子 ¾易进行亲电取代反应 芳香性

I1,Aromaticity and Reactivity ■4.芳香性判别(Huckel rules) >闭合的共轭体系（环状π电子流） >4n+2 Cyclopentadienyl Anion Planar... 6πelectrons, therefore aromatic

I1、 Aromaticity and Reactivity „4.芳香性判别(Hückel rules) ¾闭合的共轭体系(环状π电子流) ¾4n+2