Teaching Design of p–π Conjugation in Blended Teaching of Pharmaceutical Organic Chemistry

Feng Lijuan,, Wang Wenjun, Qi Baohui, Xiang Canhui

 基金资助: 贵州省高等学校教学内容和课程体系改革项目.  2019119贵州省普通本科高校课程思政教学改革研究项目.  202119

Received: 2021-10-18   Accepted: 2021-11-29

Abstract

The understanding and application of pπ conjugation effect is very important for students of pharmaceutical major to learn the chemical properties of organic compounds, but most students can't understand and apply the knowledge by traditional teaching method. Blended teaching has the advantages of traditional teaching and modern information technology teaching mode. Based on the student-centered modular blended teaching of pharmaceutical organic chemistry, the blended teaching program of pπ conjugate is designed. Firstly, the learning objectives of knowledge, ideology and politics are set. And then the network learning content are designed, including the formation conditions of pπ conjugate system, the connotation of pπ conjugate effect and the application of pπ conjugate effect. Meanwhile, the test problems are posted on the learning platform to examine the learning effect. The classroom discussion is carried out around the knowledge objectives, as well as ideological and political objectives to solve students' problems. In the whole process, learning and teaching feedback should be carried out in time, and then teaching will be adjusted and improved according to students' learning, so as to realize student-centered teaching and enable students to learn effectively, systematically and actively.

Keywords： Pharmaceutical organic chemistry ; pπ conjugation ; Blended teaching ; Teaching design ; Student-centered

Feng Lijuan. Teaching Design of pπ Conjugation in Blended Teaching of Pharmaceutical Organic Chemistry. University Chemistry[J], 2022, 37(4): 2110051-0 doi:10.3866/PKU.DXHX202110051

2.1 p–π共轭体系的形成条件

pπ共轭体系形成的条件一是有机化合物中必须有π键和p轨道；二是p轨道与π键直接相连，且与形成π键的p轨道平行。

3.1 判断题

(1) pπ共轭体系就是p轨道与π键的p轨道平行，从侧面重叠构成的。

(2) 中苯环具有闭合大π键，Br具有p轨道，所以形成了pπ共轭体系。

(3) 溴乙烯存在pπ共轭，溴对体系而言是吸电子的共轭效应(−C)。

(4) 苯酚分子中由于存在吸电子的pπ共轭效应，所以苯环上的电子云密度降低。

(5) 溴乙烯与硝酸银的醇溶液加热发生反应，生成$\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{ONO}_{2}$和AgBr沉淀。

(6) $\mathrm{CH}_{2}=\mathrm{CH}-\stackrel{+}{\mathrm{C}}{\mathrm{H}}-\mathrm{CH}_{3}$的稳定性较$\mathop {\rm{C}}\limits^ + {{\rm{H}}_2} - {\rm{C}}{{\rm{H}}_2} - {\rm{CH}} = {\rm{C}}{{\rm{H}}_2}$的低。

(7) 烯丙基氯与硝酸银的醇溶液不能发生亲核取代反应。

(8) 苯酚具有弱酸性是因为O与苯环形成了pπ共轭体系，氧氢键的极性增大，容易断裂，给出H+而呈弱酸性。(资料：酚中O为sp2杂化，有一条没有杂化的p轨道，此没有杂化的p轨道上有两个电子，即有一对孤对电子。)

3.2 选择题

(1) 下列哪些分子中不存在pπ共轭体系：

(2) 下列哪些分子中不存在pπ共轭体系：

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