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Stereoinvertive SN1 Through Neighboring Group Participation
Rahul Suresh1, Noam Orbach1, Ilan Marek1
1Schulich Faculty of Chemistry and the Resnick Sustainability Center for Catalysis, Technion - Israel Institute of Technology, Technion City, Haifa, 3200009, Israel.
Angewandte Chemie (International Ed. in English)
|May 19, 2024
Summary
Neighboring group participation typically causes stereoretention in reactions. This review explores overlooked instances where it uniquely leads to stereoinversion, offering new perspectives on controlling chemical outcomes.
Area of Science:
- Organic Chemistry
- Stereochemistry
Background:
- Neighboring group participation is a key concept in nucleophilic substitution reactions.
- It often results in rate acceleration, first-order kinetics (SN1), and stereoretention via double inversion.
- Stereoretention is widely utilized in organic synthesis for controlling stereochemical outcomes.
Purpose of the Study:
- To review the less-recognized phenomenon of stereoinversion caused by neighboring group participation.
- To categorize reactions involving neighboring group participation leading to inversion.
- To provide a fresh perspective on factors influencing stereochemical outcomes in these reactions.
Main Methods:
- Literature review of organic reactions involving neighboring group participation.
- Classification of reactions based on their stereochemical outcome (inversion vs. retention).
- Analysis of mechanistic pathways and controlling factors for stereoinversion.
Main Results:
- Identified and classified three distinct modes of stereoinversion via neighboring group participation.
- Highlighted specific reaction conditions and structural features that favor inversion over retention.
- Demonstrated that neighboring group participation can lead to both stereoretention and stereoinversion.
Conclusions:
- Neighboring group participation is a versatile phenomenon with diverse stereochemical consequences.
- Understanding the factors controlling inversion is crucial for synthetic organic chemistry.
- This review offers a new framework for analyzing and predicting stereochemical outcomes in neighboring group participation reactions.
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