Synthesis and Structural Elucidation of Diversely Functionalized 5,10-Diaza[5]Helicenes

摘要

Diversely functionalized diaza[5]helicenes have been synthesized starting from 6,9-dichloro-5,10-diaza[5]helicene,nwhich was prepared from a readily available quinoline building block via Wittig reaction followed by photochemicalnelectrocyclization. The helicene skeleton was substituted by a variety of O-, S-, N-, and C-centered nucleophiles usingnnucleophilic aromatic substitution reactions and palladium-catalyzed reactions like Suzuki coupling and Buchwald−Hartwignaminations. We have determined, using X-ray single-crystal diffraction, the crystal structures of the chloro- and methoxysubstitutedndiaza[5]helicenes. A resolution strategy based on diastereomeric separation by substitution of the dichloro derivativenwith a chiral amine has been shown.