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

• Published in: Journal of organic chemistry 2012-11, Vol.77 (22), p.10176-10183
• Main Authors: Waghray, Deepali, Zhang, Jing, Jacobs, Jeroen, Nulens, Wienand, Basarić, Nikola, Meervelt, Luc Van, Dehaen, Wim
• Format: Article
• Language: English
• Subjects: Amines - chemistry; Catalysis; Chemistry; Condensed benzenic and aromatic compounds; Crystallography, X-Ray; Exact sciences and technology; General and physical chemistry; Heterocyclic compounds; Heterocyclic compounds with only one n hetero atom and condensed derivatives; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Molecular Structure; Organic chemistry; Palladium - chemistry; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Polycyclic Compounds - chemical synthesis; Polycyclic Compounds - chemistry; Preparations and properties; Stereoisomerism
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo301814m

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.