jo0501036_si_003.pdf (5.34 MB)
Direct, Two-Step Synthetic Pathway to Novel Dibenzo[a,c]phenanthridines
journal contributionposted on 2005-04-15, 00:00 authored by Fátima Churruca, Raul SanMartin, Mónica Carril, Miren Karmele Urtiaga, Xavier Solans, Imanol Tellitu, Esther Domínguez
Novel dibenzo[a,c]phenanthridines are prepared regioselectively by the application of a straightforward synthetic pathway, starting from new 3,4-diaryl- and 3,4-dihydro-3,4-diarylisoquinolines prepared via Ritter-type heterocyclization and the more classical two-step reductive amination/Bischler−Napieralski cyclization of triarylethanones, respectively. A comparative study of nonphenolic oxidative coupling methodologies provides a highly efficient procedure, based on the hypervalent iodine reagent phenyliodine(III) bis(trifluoroacetate) (PIFA), to accomplish the final coupling step.