title: Oxahelicene NHC ligands in the asymmetric synthesis of nonracemic helicenes.
abstract: A straightforward approach to enantiopure 2H-pyran-modified amino[5]helicenes and amino[6]helicenes was developed. They were converted to 1,3-disubstituted imidazolium salts and used as NHC ligand precursors in the Ni0-catalysed enantioselective [2+2+2] cycloisomerisation of aromatic triynes to obtain the model helicene derivatives in up to 86% ee.
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 stary@uochb.cas.cz.
authors.forename: Isabel Gay
authors.initials: IG
authors.lastname: Sánchez
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 stary@uochb.cas.cz.
authors.forename: Michal
authors.initials: M
authors.lastname: Šámal
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 stary@uochb.cas.cz.
authors.forename: Jindřich
authors.initials: J
authors.lastname: Nejedlý
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 stary@uochb.cas.cz.
authors.forename: Manfred
authors.initials: M
authors.lastname: Karras
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 stary@uochb.cas.cz.
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. stara@uochb.cas.cz stary@uochb.cas.cz.
authors.forename: Jiří
authors.initials: J
authors.lastname: Rybáček
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 stary@uochb.cas.cz.
authors.forename: Miloš
authors.initials: M
authors.lastname: Buděšínský
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 stary@uochb.cas.cz.
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. stara@uochb.cas.cz stary@uochb.cas.cz.
authors.forename: Beata
authors.initials: B
authors.lastname: Seidlerová
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 stary@uochb.cas.cz.
authors.forename: Irena G
authors.initials: IG
authors.lastname: Stará
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 stary@uochb.cas.cz.
authors.forename: Ivo
authors.identifier: http://orcid.org/0000-0002-5468-3148
authors.initials: I
authors.lastname: Starý