Generation of pyrrolo[2,1-a]isoquinoline derivatives from N-ylides: Synthetic control and structural characterization

Abstract

New pyrrolo[2,1-a]isoquinolines were obtained by two one-pot procedures via 1,3-dipolar cycloaddition between the isoquinolinium N-ylides and symmetrical acetylenic dipolarophiles, avoiding the formation of dihydro intermediates. For structural comparison, the dihydro derivatives obtained by a classical two-stage reaction were characterized by NMR and X-ray crystallography, allowing complete stereochemistry assignments. © 2011 Wiley Periodicals, Inc.