82937-06-2Relevant academic research and scientific papers
REGIOCHEMICAL ASPECTS ASSOCIATED WITH THE CYCLOADDITION OF DIAZOPYRAZOLINONES TO ELECTRON DEFICIENT ACETYLENES
Woolhouse, Anthony D.,Caruso, Thomas C.,Padwa, Albert
, p. 2167 - 2170 (1982)
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.
1,3-Dipolar Cycloaddition Reactions of Diazopyrazolinones with Electron-Deficient Dipolarophiles
Padwa, Albert,Woolhouse, Anthony D.,Blount, John J.
, p. 1069 - 1074 (2007/10/02)
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.
