Synfacts 2009(6): 0599-0599  
DOI: 10.1055/s-0029-1216712
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of 2-Aminopyrroles by Sequential MCR/[4+1] Cycloaddition

Contributor(s): Victor Snieckus, Cédric Schneider
P. Fontaine, G. Masson*, J. Zhu*
Institut de Chimie des Substances Naturelles, Gif-sur-Yvette, France
Further Information

Publication History

Publication Date:
25 May 2009 (online)

Significance

Reported is an efficient two-step synthesis of unsymmetrical polysubstituted 2-aminopyrroles from α,β-unsatured aldehydes. By combining a [4+1] cycloaddition with the oxidative three-component Strecker reaction developed previously by Zhu for the synthesis of α-imino­nitriles 2 (P. Fontaine, A. Chiaroni, G. Masson, J. Zhu Org. Lett. 2008, 10, 1509), diversely substituted pyrroles 3 have been readily prepared. Indeed, after optimization of the [4+1] cycloaddition, a considerable number of aromatic and aliphatic isocyanides was studied, affording 2-amino-5-­cyanopyrroles in good to excellent yield. However, in the presence of α-isocyanoacetamide 5, a Michael addition reaction occurred to afford the oxazole 6.