Pericyclic Reactions
Module Overview
This module teaches fundamentals of pericyclic reactions using examples of biocatalysis, biomimetic catalysis, and natural product total synthesis. After completion, students should be able to identify key disconnections of pericyclic reactions (specifically [4+2] and [2+2] cycloadditions, as well as [3,3]-sigmatropic rearrangements) for the preparation of agrochemicals and natural products (SDG 2: Zero Hunger) and pharmaceuticals (SDG 3: Good Health and Well-Being).
Module Goal
Through this module, students will be able to identify key disconnections for pericyclic reactions, as well as compare and contrast synthetic routes involving pericyclic reactions. Students will also apply pericyclic reactions in understanding the synthesis of pharmaceuticals and agrochemicals, analyze the role of biomolecules and supramolecules as catalysts for pericyclic reactions, and explore the role of pericyclic reactions in biogenesis of complex molecules.
Audience
First-semester organic chemistry undergraduates
Class Time Requirement
Approximately two consecutive class periods
Module Authors
Dr. Yalan Xing, Hofstra University; Dr. Michael C. Young, The University of Toledo
Module Summary
Assumed Prior Knowledge
Students should be able to demonstrate the following skills and concepts to successfully begin this module:
- Knowledge of alkene nomenclature and reactivity
- Knowledge of resonance and hyperconjugative effects
- Skill drawing organic reaction mechanisms
- Skill evaluating retrosynthetic disconnections
- Atom Economy and Process Mass Intensity Calculations
Learning Objectives
Students will be able to:
- Identify disconnections for pericyclic reactions, including the Diels-Alder and [3,3]-sigmatropic rearrangements, as well as explain and apply the mechanisms of different pericyclic reactions and derive the reaction products based on provided starting materials and reaction conditions.
- Recognize the reaction conditions required for different pericyclic reactions, including thermal, catalytic (Lewis acid catalysis and biocatalysis), and photo conditions, as well as identify green reaction conditions based on green chemistry principles.
- Identify cyclic fragments that can be synthesized by pericyclic reactions in complex bio-active molecules
- Compare the sustainability of pericyclic reactions with regard to atom economy and process mass intensity.
- Describe the advantages and disadvantages of different types of catalysis (Lewis acid, Biocatalytic, “On-Water”) on the sustainability of pericyclic reaction strategies in complex molecule synthesis.
- Discuss the societal benefits and drawbacks of applying pericyclic reactions to human well-being through SDG 2 and SDG 3.
Unit Overview
Unit 1: Physical Properties and Applications in Fuel Chemistry
1.1 | Lecture (30 minutes): Lecture slides introducing [4 + 2] cycloaddition reactions. |
1.2 | Group Discussion (20 minutes) on a practice problem involving system thinking. |
1.3 | Small group in-class practice problems (15 mnutes). Summative Assessment 1 (20 minutes). |
Unit 2: [3,3]-Sigmatropic Rearrangements
2.1 | Lecture (15 minutes): Introduction to sigmatropic rearrangements. |
2.2 | Group Discussion (45 minutes): Group discussion on a practice problem involving system thinking. Summative Assessment 2 (20 minutes). |
Download Module
Pericyclic Reactions Includes:
- Module Overview Document
- Units 1-2
- Formative Assessments
- Summative Assessments
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About the Green Chemistry Module Project
The ACS Green Chemistry Instiute has partnered with chemistry instructors from over 45 institutions to develop green chemistry education resources for undergraduate students studying general and organic chemistry.
