Reaction between 1,10-Phenanthroline and Dialkyl Acetylenedicarboxylates. A Facile Synthetic Route to Helical Dipyrrolophenanthrolines†

Abstract

1,10-Phenanthroline and its 5-substituted derivatives react with dialkyl acetylenedicarboxylates to give dipyrrolo[1,2-a:2′,1′-k][1,10]phena nthroline derivatives, which exhibit nonplanarity enforced by the crowding of the ester groups.