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Published on: May 21, 2019
Copper-catalysed site-selective arylation of pyrazoles
Minghao Wang1, Xintong Hou1, Stephanie A Corio2
1Department of Chemistry, University of California, Irvine, Irvine, CA, USA.
Nature Chemistry
|June 12, 2026
Summary
Researchers developed a new copper-catalyzed method for selective N-arylation of pyrazoles, enabling switchable functionalization of these important drug molecules. This breakthrough overcomes limitations in traditional methods, facilitating drug discovery.
Area of Science:
- Organic Chemistry
- Medicinal Chemistry
- Catalysis
Background:
- Selective N-arylation of unsymmetric pyrazoles is a significant challenge in late-stage functionalization.
- Pyrazoles are crucial scaffolds in many pharmaceuticals and bioactive compounds.
- Existing cross-coupling methods often lack regioselectivity, hindering access to diverse chemical structures.
Purpose of the Study:
- To develop a novel method for switchable and selective N-arylation of unsymmetric pyrazoles.
- To overcome the regioselectivity limitations of traditional cross-coupling reactions.
- To enable efficient late-stage functionalization for drug discovery and structure-activity relationship studies.
Main Methods:
- Utilizing copper catalysis in conjunction with arynes for pyrazole arylation.
- Tuning copper-pyrazole coordination to control site selectivity.
- Conducting mechanistic studies to understand regioselectivity determinants.
Main Results:
- Achieved switchable N-arylation of pyrazoles under mild conditions.
- Demonstrated high regioselectivity by directing arylation to specific nitrogen atoms.
- Identified steric and electronic factors governing regioselectivity.
Conclusions:
- Developed a general strategy for site-selective functionalization of nitrogen-rich heterocycles.
- Established copper catalysis with arynes as a powerful tool for accessing diverse pyrazole derivatives.
- Highlighted the utility of strained intermediates in late-stage molecular diversification.
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