| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 5270938 | Tetrahedron Letters | 2010 | 4 Pages |
Abstract
We describe the synthesis of diverse pyrazoles by 1,3-dipolar cycloaddition of ethyl diazoacetate with various acetylenes in refluxing toluene. The product pyrazoles are useful starting points for preparing a diverse collection of trisubstituted pyrazole carboxamides. For aryl and heteroaryl alkynes a single product is obtained while alkyl alkynes afford a ca. 6:1 mixture of regioisomers. The observed regioselectivity for the cycloaddition step and the ease of reaction are consistent with predictions derived from computing the HOMO-LUMO energies of the reactants.
Related Topics
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Authors
Kwai Ming J. Cheung, Jóhannes Reynisson, Edward McDonald,