7,8,9,10-Tetrahydropyrrolo[2,1-a]isoquinolines in the search for new indolizine derivatives

7,8,9,10-Tetrahydropyrrolo[2,1-a]isoquinolines were obtained by 1,3-dipolar cycloaddition reactions of their corresponding N-ylides with olefinic (acrylonitrile) and symmetrical or non-symmetrical acetylenic dipolarophiles (methyl/ethyl propiolate, dimethyl acetylenedicarboxylate). Also, stable 5,6,7,8-tetrahydroisoquinolinium dicyanomethylide was isolated and characterized by X-ray diffraction analysis.