1,3-Dipolar Cycloadditions of Trimethylsilyldiazomethane Revisited: Steric Demand of the Dipolarophile and the Influence on Product Distribution
The 1,3-dipolar cycloaddition of trimethylsilyldiazomethane with α,β-unsaturated esters was examined. The resulting 1-pyrazolines isomerize to regioisomeric 2-pyrazolines (a or b) or undergo desilylation (c). Acrylates yield only b or c. β-Substituted dipolarophiles may yield all three types of prod...
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Published in | Journal of organic chemistry Vol. 72; no. 2; pp. 650 - 653 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
WASHINGTON
American Chemical Society
19.01.2007
Amer Chemical Soc |
Subjects | |
Online Access | Get full text |
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Summary: | The 1,3-dipolar cycloaddition of trimethylsilyldiazomethane with α,β-unsaturated esters was examined. The resulting 1-pyrazolines isomerize to regioisomeric 2-pyrazolines (a or b) or undergo desilylation (c). Acrylates yield only b or c. β-Substituted dipolarophiles may yield all three types of products. This work demonstrates that the distribution of 2-pyrazoline products is highly dependent on the relative configuration of the substituents on the 1-pyrazoline intermediate. |
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Bibliography: | istex:B286F34EADB96891F16F37C05F8A87C1F67D95DC ark:/67375/TPS-D7ZD8W85-4 Medline NIH RePORTER ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0022-3263 1520-6904 |
DOI: | 10.1021/jo061838t |