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Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium Under Mild Reaction Conditions
Published on: March 20, 2014
Mechanism of the Pummerer reaction: a computational study
Mahendra Patil1, Claudia Loerbroks, Walter Thiel
1Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany.
Organic Letters
|March 26, 2013
Summary
This study uses DFT calculations to reveal the rate-determining step in the Pummerer reaction. It explores how additives like TMSOTf and DMAC influence stereoselective reaction pathways.
Area of Science:
- Organic Chemistry
- Computational Chemistry
Background:
- The Pummerer reaction is a fundamental organic transformation involving sulfoxides.
- Understanding its mechanism, especially under stereoselective conditions, is crucial for synthetic applications.
Purpose of the Study:
- To elucidate the reaction mechanism of the Pummerer reaction between a chiral sulfoxide and acetic anhydride.
- To investigate the role of additives, such as trimethylsilyl triflate (TMSOTf) and N,N-dimethylacetamide (DMAC), in stereoselective Pummerer reactions.
Main Methods:
- Density Functional Theory (DFT) calculations were employed to model the reaction pathways.
- Analysis of transition states and intermediate species was performed.
Main Results:
- The initial acetylation of the sulfoxide, with acetate release, was identified as the rate-determining step in both classical and stereoselective conditions.
- TMSOTf and DMAC were shown to facilitate stereoselective pathways through assisted transition states and ion exchange mechanisms.
Conclusions:
- The rate-determining step of the Pummerer reaction is consistently the initial sulfoxide acetylation.
- Additives play a significant role in controlling stereoselectivity by influencing reaction intermediates and transition states.
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