指向证据推理与模型认知的“有机反应再认识”教学

“Organic Reaction”Teaching Aimed at Evidence-Based Reasoning and Model-Based Thinking

从化学键断裂方式对有机反应进行分类,将化学反应分为非极性反应和极性反应,引导学生通过电子云密度分布不均和电负性的不同构建由化学键异裂引起的极性反应的模型,总结极性反应中取代反应和以醛酮为代表的极性π键的加成反应模型。采取小组讨论的形式,引导学生基于模型重新认识教材中的已有反应;基于极性反应的模型,引导学生自主构建碳碳键的形成反应,完成由已知到未知的迁移;最后,基于极性反应的模型和碳碳键的形成进行在有机合成方面的综合应用,目的是使学生形成对有机合成路线设计的整体认识,从而从本质上进一步认识有机反应,培养学生对有机反应认识的高阶思维。

In this paper,organic reactions are classified by the way of breaking chemical bonds.Chemical reactions are divided into non-polar reactions and polar reactions.Students are guided to construct models of polar reactions caused by hetero-cracking of chemical bonds through the uneven distribution of electronic clouds and the difference of electronegativity.Substitution reactions in polar reactions and additive reaction models of polar π bonds represented by aldehydes and ketones are summarized.In the form of group discussion,students are guided to reanalyze the existing reactions in textbooks based on models;based on polar reaction models,students construct the formation reaction of carbon-carbon bonds independently,which is a part of the migration from known to unknown;finally,based on polar reaction models and the formation of carbon-carbon bonds,comprehensive application of organic synthesis is carried out to enable students to form a pathway for organic synthesis.