Enantioselective Dearomative Cyclization Enabled by Asymmetric Cooperative Gold Catalysis
Ke Zhao1, Philip Kohnke1, Ziguang Yang1
1Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA.
Angewandte Chemie (International Ed. in English)
|July 17, 2022
Summary
A novel gold(I) catalysis enables enantioselective dearomatization using chiral ligands. This method efficiently synthesizes valuable chiral binaphthyl phosphines for broad applications in naphthols and phenols, achieving high enantiomeric excesses.
Area of Science:
- Organic Chemistry
- Catalysis
- Asymmetric Synthesis
Background:
- Dearomatization reactions are crucial for synthesizing complex molecules.
- Developing efficient enantioselective methods remains a key challenge in organic synthesis.
- Metal-chiral ligand cooperation offers a powerful strategy for controlling stereochemistry.
Purpose of the Study:
- To develop a gold(I)-catalyzed enantioselective dearomatization reaction.
- To synthesize novel chiral bifunctional binaphthyl-2-ylphosphine ligands.
- To broaden the substrate scope of this dearomatization chemistry.
Main Methods:
- Gold(I) catalysis with chiral phosphine ligands.
- Divergent synthesis of binaphthyl-2-ylphosphine ligands.
- Application to naphthols, 2-naphthols, and phenols.
- Density Functional Theory (DFT) calculations.
Main Results:
- Achieved enantioselective dearomatization via metal-chiral ligand cooperation.
- Developed a rapid synthesis for chiral binaphthyl-2-ylphosphine ligands.
- Demonstrated broad substrate scope with high enantiomeric excesses (up to 98%).
- DFT calculations supported the proposed cooperative catalysis mechanism.
Conclusions:
- The developed gold(I) catalytic system is effective for enantioselective dearomatization.
- The new chiral ligands enable efficient synthesis of valuable chiral compounds.
- Hydrogen bonding plays a key role in achieving high stereoselectivity.
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