title: Novel synthesis of highly functionalized pyrazolines and pyrazoles by triphenylphosphine-mediated reaction of dialkyl azodicarboxylate with allenic esters.
abstract: [reaction: see text] 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...O interactions. Pyrazole formation proceeds via a novel nitrogen to carbon migration of the carboalkoxy group.
authors.affiliation: Organic Chemistry Section, Regional Research Laboratory (CSIR), Trivandrum, India. vijaynair_2001@yahoo.com
authors.forename: Vijay
authors.initials: V
authors.lastname: Nair
authors.forename: A T
authors.initials: AT
authors.lastname: Biju
authors.forename: Kishor
authors.initials: K
authors.lastname: Mohanan
authors.forename: Eringathodi
authors.initials: E
authors.lastname: Suresh