ChemInform Abstract: Highly Efficient Regioselective Synthesis of Pyrroles via a Tandem Enamine Formation—Michael Addition—Cyclization Sequence under Catalyst‐ and Solvent‐Free Conditions.

Abstract

Free Conditions. -A convenient catalyst-free, three-component procedure is developed for the synthesis of tetrasubstituted pyrroles under solvent-free conditions and in green solvents glycerol, PEG-200 and water. A sequence involving enamine--formation, Michael addition, and intramolecular cyclization of primary amines with 1,3-dicarbonyl compounds and isatin-derived Michael acceptors affords (pyrrol-3-yl)indolin-2-ones in high yields. Best results are achieved under neat conditions. Compound (IIIa) shows significant in vitro cytotoxicity against Ehrlich's ascites carcinoma tumor cells. -(VIVEKANAND, T.; VINOTH, P.; AGIESHKUMAR, B.; SAMPATH, N.; SUDALAI, A.; MENENDEZ, J. C.; SRIDHARAN*, V.; Green Chem. 17 (2015) 6, 3415-3423, http://dx.