Amide-stabilized enols in the enol-Ugi reaction: a five-component synthesis of triamides

In continuation with our research in the use of enols in multicomponent reactions with isocyanides (IMCR), we have used for the first time amide-stabilized enols as the acid component in enol-Ugi reactions. Thus, the reaction of 2-(hydroxy(phenylamino)methylene)-5,5-dimethylcyclohexane-1,3-dione with aldehydes, amines and isocyanides provides the expected enamine adducts. On the other hand, the use of analogous Meldrum’s acid-derived enols permits the synthesis of triamides by a five-component process with the participation of a molecule of solvent. These results confirm the great potential of the enol-Ugi reaction for the preparation of a wide variety of structures containing a peptidomimetic scaffolds.