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Millifluidics for Chemical Synthesis and Time-resolved Mechanistic Studies
Published on: November 27, 2013
Fluxional additives: a second generation control in enantioselective catalysis
Mukund P Sibi1, Shankar Manyem, Hector Palencia
1Department of Chemistry and Molecular Biology, North Dakota State University, Fargo, North Dakota 58105, USA. Mukund.Sibi@ndsu.edu
Journal of the American Chemical Society
|October 19, 2006
Summary
New fluxional additives can adopt different shapes based on chiral ligands, improving enantioselective reactions like Diels-Alder and nitrone cycloadditions. These modular additives enhance chiral Lewis acid catalysis for better selectivity.
Area of Science:
- Organic Chemistry
- Asymmetric Catalysis
Background:
- Enantioselective synthesis is crucial for pharmaceuticals and fine chemicals.
- Developing novel additives to control stereochemistry remains a key challenge in catalysis.
Purpose of the Study:
- To introduce and demonstrate the utility of "fluxional additives" in asymmetric catalysis.
- To showcase the modular design and accessibility of these novel additives.
- To investigate their impact on enantioselectivity in Diels-Alder and nitrone cycloaddition reactions.
Main Methods:
- Design and synthesis of modular fluxional additives.
- Application of additives in enantioselective Diels-Alder reactions.
- Application of additives in enantioselective nitrone cycloaddition reactions.
- Evaluation of enantioselectivity using chiral Lewis acids (main group and transition metals).
Main Results:
- Demonstrated the concept of fluxional additives adapting conformation based on chiral ligand information.
- Achieved enhanced enantioselectivity in Diels-Alder and nitrone cycloaddition reactions.
- Showcased the modularity of additive design, with diverse structures accessible in three steps.
- Observed improved performance of chiral Lewis acids in the presence of these additives.
Conclusions:
- Fluxional additives represent a novel strategy for controlling stereochemistry in asymmetric reactions.
- The modular design allows for facile synthesis and tuning of additive properties.
- These additives significantly enhance the enantioselectivity achieved with various chiral Lewis acid catalysts.
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