Ni(II)-catalyzed enantioselective Nazarov cyclizations
1Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, ETH Zurich, CH-8093 Zurich, Switzerland.
Chemical Communications (Cambridge, England)
|September 20, 2008
Summary
A novel nickel(II) catalyst with chiral phosphine ligands enables highly selective Nazarov cyclizations. This new method achieves excellent enantioselectivity, producing valuable chiral compounds.
Area of Science:
- Organometallic Chemistry
- Asymmetric Catalysis
Background:
- Nazarov cyclization is a key reaction for synthesizing cyclopentenones.
- Developing efficient and selective catalysts for Nazarov cyclizations remains a challenge.
Purpose of the Study:
- To develop a novel chiral catalyst for asymmetric Nazarov cyclizations.
- To investigate the catalytic activity and selectivity of the new system.
Main Methods:
- Synthesis of a dicationic Ni(II) complex featuring the chiral tridentate phosphine ligand Pigiphos.
- Application of the catalyst in Nazarov cyclization reactions.
Main Results:
- The Ni(II)-Pigiphos catalyst effectively promotes Nazarov cyclizations.
- High torquoselectivity was observed, leading to products with up to 88% enantiomeric excess (ee).
Conclusions:
- The dicationic Ni(II) complex with Pigiphos is a highly effective catalyst for asymmetric Nazarov cyclizations.
- This catalyst offers a promising route to enantiomerically enriched cyclopentenones.
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