Mechanisms before Reactions: A Mechanistic Approach to the Organic Chemistry Curriculum Based on Patterns of Electron Flow
Mechanisms before Reactions: A Mechanistic Approach to the Organic Chemistry Curriculum Based on Patterns of Electron Flow
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DOI：
10.1021/ed500284d
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发表时间：
2015-05-01
影响因子：
3
通讯作者：
Ogilvie, William W.
中科院分区：
文献类型：
--
作者：
Flynn, Alison B.;Ogilvie, William W.
介绍了作者所在机构的有机化学导论课程的重大重新设计。有两个方面与典型有很大的不同。功能组方法。首先，有机反应机制和电子推动形式主义教之前，学生已经学会了一个单一的反应。电子、原子和形式电荷的守恒定律。曲线箭头的使用有助于描述反应机理，并强调了如何预测反应机理。第二，前两个学期有机化学中教授的反应是按其控制机理排列的，而不是按官能团排列的。这些反应是按照难度增加的顺序来教授的，从酸碱反应开始，然后是对π亲电体的简单加成，最后是对π亲核体的加成，包括芳香化学。第二有机学期的反应开始是消除反应，然后是取代，最后是更复杂的pi亲核机制（例如，羟醛缩合反应）和亲电子试剂反应（例如，缩醛）。最终，目标是让学生根据他们的反应模式学习和解释反应，使他们能够分析，预测和解释新的反应。原则上，机械方法更通用，更容易理解，并提供了更好的方法来深入了解化学反应性。化学反应遵循模式，这些模式可以让化学家预测化学品的行为，即使他们以前从未见过特定的反应。将反应性可视化为电子运动模式的集合是一种更强大和更系统的方法来学习有机化学。它仍然需要一些记忆，但由于课程组织与反应模式直接相关，因此可以在该学科中进行更深入的学习。
A significant redesign of the introductory organic chemistry curriculum at the authors' institution is described. There are two aspects that differ greatly from a typical. functional group approach. First, organic reaction mechanisms and the electron-pushing formalism are taught before students have learned a single reaction. The conservation of electrons, atoms, and formal charges, how. the use of curved arrows helps describe the mechanism, and how to predict reaction mechanisms are emphasized. Second, the reactions taught in the first two semesters of organic chemistry are arranged by their governing mechanism, rather than by functional group. The reactions are taught in order of increasing difficulty, beginning with acid-base reactions, followed by simple additions to pi electrophiles, and ending the first semester with addition to pi nudeophiles, including aromatic chemistry. The reactions in the second organic semester begin with elimination reactions, then substitutions, and finally more complex pi nudeophile mechanisms (e.g., aldol reaction) and pi electrophile reactions (e.g., acetals). Ultimately, the goal is for students to learn and interpret reactions based on their patterns of reactivity, allowing them to analyze, predict, and explain new reactions. In principle, a mechanistic method is more general, easier to understand, and provides a better way to achieve a deep understanding of chemical reactivity. Chemical reactions follow patterns, and these patterns can allow a chemist to predict how a chemical will behave, even if they have never seen a particular reaction before. Visualizing reactivity as a collection of patterns in electron movement is a more powerful and systematic way to approach learning in organic chemistry. It still requires some memorization, but because the course organization is directly linked to reaction patterns, deeper learning in the discipline is possible.