P. Prasanna, S. Perumal, J. Menéndez
Apr 29, 2013
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0
Influential Citations
67
Citations
Journal
Green Chemistry
Abstract
A library of 4H-pyrano[2,3-c]pyrazol-6-amines was synthesized in excellent yield employing an L-proline-catalyzed, on-water four-component domino reaction from hydrazines, β-dicarbonyl compounds, nitriles and dialkyl acetylenedicarboxylates that generates two rings by the creation of C–C (two), C–N, CN and C–O bonds and presumably involves a sequence of hydrazone formation, cyclocondensation, Michael, [1,3]-hydrogen shift, Michael addition and 6-exo-dig annulation steps. When alkyl propiolates were employed, a three-component reaction took place furnishing alkyl 3,3-bis(5-hydroxy-1H-pyrazol-4-yl)propanoates via a double Michael domino process.