Novel synthesis of highly functionalized pyrazolines and pyrazoles by triphenylphosphine-mediated reaction of dialkyl azodicarboxylate with allenic esters.
[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.
Nair
Vijay
V
Organic Chemistry Section, Regional Research Laboratory (CSIR), Trivandrum, India. vijaynair_2001@yahoo.com
Biju
A T
AT
Mohanan
Kishor
K
Suresh
Eringathodi
E