82937-07-3Relevant academic research and scientific papers
1,3-Dipolar Cycloaddition Reactions of Diazopyrazolinones with Electron-Deficient Dipolarophiles
Padwa, Albert,Woolhouse, Anthony D.,Blount, John J.
, p. 1069 - 1074 (1983)
A study of the reactivity of a series of 4-diazopyrazolin-5-ones toward dipolar cycloaddition with electron-deficient olefinic and acetylenic dipolarophiles has been carried out.Reactions with dimethyl acetylenedicarboxylate afford pyrazolotriazin-7-ones which result from dipolar cycloaddition followed by a van Alphen-Huttel rearrangement of the initially produced spiro 3H-pyrazole adducts.Reaction with unsymmetrical acetylenic esters afforded variable mixtures of regioisomeric pyrazolotriazinones and 1H-furopyrazoles.Product formation has been rationalized in terms of a sustituent-dependent partitioning between spiro 3H-pyrazole adducts and ring-opened diazoalkanes.Spirocarboxylate esters were the only products isolated from reactions with acrylate ester.
REGIOCHEMICAL ASPECTS ASSOCIATED WITH THE CYCLOADDITION OF DIAZOPYRAZOLINONES TO ELECTRON DEFICIENT ACETYLENES
Woolhouse, Anthony D.,Caruso, Thomas C.,Padwa, Albert
, p. 2167 - 2170 (2007/10/02)
The regiospecificity with which members of the 4-diazopyrazolin-5-one system undergo intermolecular cycloaddition to propiolate ester has been found to be markedly dependent upon the substituent groups present.
