title: Synthesis and structural elucidation of diversely functionalized 5,10-diaza[5]helicenes.
abstract: Diversely functionalized diaza[5]helicenes have been synthesized starting from 6,9-dichloro-5,10-diaza[5]helicene, which was prepared from a readily available quinoline building block via Wittig reaction followed by photochemical electrocyclization. The helicene skeleton was substituted by a variety of O-, S-, N-, and C-centered nucleophiles using nucleophilic aromatic substitution reactions and palladium-catalyzed reactions like Suzuki coupling and Buchwald-Hartwig aminations. We have determined, using X-ray single-crystal diffraction, the crystal structures of the chloro- and methoxy-substituted diaza[5]helicenes. A resolution strategy based on diastereomeric separation by substitution of the dichloro derivative with a chiral amine has been shown.
authors.affiliation: Molecular Design and Synthesis, Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium.
authors.forename: Deepali
authors.initials: D
authors.lastname: Waghray
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Jeroen
authors.initials: J
authors.lastname: Jacobs
authors.forename: Wienand
authors.initials: W
authors.lastname: Nulens
authors.forename: Nikola
authors.initials: N
authors.lastname: Basarić
authors.forename: Luc
authors.initials: L
authors.lastname: Van Meervelt
authors.forename: Wim
authors.initials: W
authors.lastname: Dehaen
mesh_terms: D000588:Amines / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry; D011083:Polycyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000588:Amines; D011083:Polycyclic Compounds; C031660:helicenes; D010165:Palladium