DOI

A wide range of derivatives with new pyrido[2,1-a]pyrrolo[3,4-c]isoquinoline skeleton was synthesized by free-radical intramolecular cyclization of o-bromophenyl-substituted pyrrolylpyridinium salts using the (TMS)3SiH/AIBN system. The cyclization provides generally good yields of pyrido[2,1-a]pyrrolo[3,4-c]isoquinoline hydrobromides having no additional radical-sensitive substituents. The free bases can be obtained from the synthesized hydrobromides in quantitative yield by basification at room temperature. The selectivity control of intramolecular arylation was achieved by replacing the halogen: the use of 1-(2-(ortho-bromo-phenyl)-4-(ortho-iodophenyl)pyrrol-3-yl)pyridinium bromide makes it possible to obtain a monocyclization product, and the bicyclization product from the dibromo derivative. The procedure is also applicable to obtain 3-arylpyrido[2,1-a]pyrrolo[3,2-c]isoquinoline derivatives including 2-unsubstituted skeletons that are inaccessible via Pd-catalyzed cyclization.

Original languageEnglish
Pages (from-to)1490-1498
Number of pages9
JournalBeilstein Journal of Organic Chemistry
Volume17
DOIs
StatePublished - 23 Jun 2021

    Scopus subject areas

  • Organic Chemistry

    Research areas

  • Arylation, Pyridine, Pyrrole, Radical cyclization, Tris(trimethylsilyl)silane, tris(trimethylsilyl)silane, radical cyclization, pyridine, arylation, pyrrole

ID: 78677826