title: [2+2+2] Cycloisomerisation of Aromatic Cyanodiynes in the Synthesis of Pyridohelicenes and Their Analogues.
abstract: We have developed a methodology for the synthesis of pyridohelicenes and their analogues based on the Ni(0) -, Co(I) - or Rh(I) -mediated intramolecular [2+2+2] cycloisomerisation of cyanodiynes. It allows for folding the linear precursors into the corresponding helical backbones comprising the newly formed pyridine unit in their central part. Along with racemic pyrido[n]helicenes (n=5,6,7) and their derivatives, both enantio- and diastereomerically pure pyrido[n]helicene-like molecules (n=5,6) were prepared by employing the chiral substrate-controlled cyclisation of the corresponding enantiopure cyanodiynes.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 166 10, Prague 6, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Klívar
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 166 10, Prague 6, Czech Republic.
authors.forename: Andrej
authors.initials: A
authors.lastname: Jančařík
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 166 10, Prague 6, Czech Republic.
authors.forename: David
authors.initials: D
authors.lastname: Šaman
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 166 10, Prague 6, Czech Republic.
authors.forename: Radek
authors.initials: R
authors.lastname: Pohl
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 166 10, Prague 6, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Fiedler
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 166 10, Prague 6, Czech Republic.
authors.forename: Lucie
authors.initials: L
authors.lastname: Bednárová
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 166 10, Prague 6, Czech Republic. stary@uochb.cas.cz.
authors.forename: Ivo
authors.initials: I
authors.lastname: Starý
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 166 10, Prague 6, Czech Republic. stara@uochb.cas.cz.
authors.forename: Irena G
authors.initials: IG
authors.lastname: Stará
keywords: aromatic compounds; chirality; helical structures; helicenes; heterocycles