@article {42467,
	title = {Novel synthesis of highly functionalized pyrazolines and pyrazoles by triphenylphosphine mediated reaction of dialkyl azodicarboxylate with allenic esters},
	journal = {Organic Letters},
	volume = {8},
	year = {2006},
	month = {MAY},
	pages = {2213{\textendash}2216},
	type = {Article},
	abstract = {<p>Reaction of the Huisgen zwitterion, derived from triphenylphosphine and dialkyl azodicarboxylate, with allenic esters affords highly functionalized pyrazolines and pyrazoles. The crystal structure of pyrazoline derivative 7a showed extensive C-H{\textperiodcentered}{\textperiodcentered}{\textperiodcentered}O interactions. Pyrazole formation proceeds via a novel nitrogen to carbon migration of the carboalkoxy group.</p>},
	doi = {10.1021/ol0604623},
	author = {Nair, Vijay and Biju, Akkattu T. and Mohanan, Kishor and Eringathodi, Suresh}
}
@article {42463,
	title = {Novel reaction of the {\textquotedblleft}huisgen zwitterion{\textquotedblright} with chalcones and dienones: an efficient strategy for the synthesis of pyrazoline and pyrazolopyridazine derivatives},
	journal = {Angewandte Chemie-International Edition},
	volume = {46},
	year = {2007},
	month = {MAR},
	pages = {2070{\textendash}2073},
	type = {Article},
	abstract = {<p>Two unexpected transformations: The reaction of the Huisgen zwitterion derived from triphenylphosphane and diisopropyl azodicarboxylate (DIAD) with chalcones affords functionalized pyrazolines. In contrast, the reaction with dienones affords pyrazolopyridazines, presumably by Diels{\textendash}Alder reaction of the initially formed pyrazoline with excess DIAD (see scheme).</p>},
	keywords = {chalcones; nitrogen heterocycles; pyrazolines; synthetic methods; zwitterions},
	doi = {10.1002/anie.200604025},
	author = {Nair, Vijay and Biju, Akkattu T. and Mathew, Smitha C. and Eringathodi, Suresh}
}
