N,N-disubstituted propargylamines as tools in the sequential 1,3-dipolar cycloaddition/arylation processes to the formation of polyheterocyclic systems

Starting from N,N-disubstituted propargylamines, through a one-pot sequential 1,3-dipolar cycloaddition/Pd-catalyzed arylation, polyheterocyclic systems were obtained in only one step. The outcome of the cycloadditions, performed with 1,3-dipoles nitriloxide and azide, was totally regioselective. The subsequent Pd-catalyzed arylation achieved using ligand-free conditions involved the unsubstituted carbon of the heterocyclic ring. (C) 2008 Elsevier Ltd. All rights reserved.