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In-plane aromaticity in double group transfer reactions
Israel Fernández1, Miguel A Sierra, Fernando P Cossío
1Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, 28040-Madrid, Spain. israel@quim.ucm.es
The Journal of Organic Chemistry
|February 10, 2007
Summary
Double group transfer reactions, including dyotropic reactions and Meerwein-Ponndorf-Verley reduction, occur through aromatic transition structures. These reactions exhibit synchronous in-plane characteristics, similar to pyrazine
Area of Science:
- Computational Chemistry
- Organic Reaction Mechanisms
- Quantum Chemistry
Background:
- Double group transfer reactions are fundamental in organic synthesis.
- Understanding their mechanisms is crucial for predicting reactivity and designing new reactions.
- Previous studies have explored various aspects, but a unified mechanistic view is lacking.
Purpose of the Study:
- To investigate the key mechanistic features of double group transfer reactions.
- To identify commonalities in the transition structures of diverse reactions within this class.
- To elucidate the role of aromaticity in the reaction pathways.
Main Methods:
- Utilizing density-functional theory (DFT) calculations.
- Analyzing the electronic structure and orbital topology of transition states.
- Comparing reaction pathways for different double group transfer processes.
Main Results:
- A wide range of double group transfer reactions, including type II-dyotropic reactions and Meerwein-Ponndorf-Verley reduction, proceed via highly synchronous in-plane aromatic transition structures.
- The orbital topology of these transition states is analogous to that of D2h-symmetric aromatic molecules like pyrazine.
- This suggests a unifying mechanistic principle based on aromaticity.
Conclusions:
- Aromatic transition structures are a common and important feature of double group transfer reactions.
- The concept of aromaticity in transition states provides a powerful framework for understanding these reactions.
- This finding can guide the development of new synthetic methodologies.
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