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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Isoxazoles from 1,1-Disubstituted Bromoalkenes
Sureshbabu Dadiboyena1, Jianping Xu, Ashton T Hamme
1Department of Chemistry, Jackson State University, Jackson, Mississippi 39217, USA.
This study presents a regioselective synthesis for 3,5-disubstituted isoxazoles. The method utilizes 1,3-dipolar cycloaddition with 1,1-disubstituted bromoalkenes, forming key intermediates that readily aromatize.
Area of Science:
- Organic Chemistry
- Heterocyclic Chemistry
Background:
- Isoxazoles are important heterocyclic compounds with diverse applications.
- Efficient synthesis of substituted isoxazoles remains a key challenge in organic chemistry.
Purpose of the Study:
- To develop a regioselective method for synthesizing 3,5-disubstituted isoxazoles.
- To explore the utility of 1,1-disubstituted bromoalkenes as alkyne synthons.
Main Methods:
- Employing 1,3-dipolar cycloaddition reactions.
- Utilizing nitrile oxides and 1,1-disubstituted bromoalkenes.
- Formation and subsequent aromatization of bromoisoxazoline intermediates.
Main Results:
- Achieved regioselective synthesis of 3,5-disubstituted isoxazoles.
- Successfully generated 5,5-disubstituted bromoisoxazoline intermediates.
- Demonstrated aromatization of intermediates via HBr elimination.
Conclusions:
- The developed method offers an effective route to 3,5-disubstituted isoxazoles.
- 1,1-disubstituted bromoalkenes are valuable synthons for constructing isoxazole frameworks.
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