Collect. Czech. Chem. Commun. 2007, 72, 1139-1157

Chiral Binaphthalenes Bearing Two Pyridine Ligands Attached Via Acetylene Spacers. Synthesis and Coordination Study

Peter Kasáka,b, Henrich Bratha, Katarína Krascsenicsová-Polákováa, Anna Kickováa, Natalia Moldovana and Martin Putalaa,*

a Department of Organic Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, 842 15 Bratislava, Slovak Republic
b Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 842 36 Bratislava, Slovak Republic


An effective methodology has been developed for the synthesis of enantiopure 2,2'-dialkynylated 1,1'-binaphthalene derivatives. Enantiopure 2,2'-diiodo-1,1'-binaphthalene (10) provided 2,2'-diethynyl-1,1'-binaphthalene (16) in the Negishi alkynylation supported by microwave irradiation in a very good yield with conservation of stereochemical information. The Stephen-Castro alkynylation of 10 afforded products in lower yields; however, in stereoconservative manner as well. Terminal diacetylene 16 served as precursor in the Sonogashira cross-coupling reaction to give new bispyridine derivatives 7-9 as potential ligands in moderate to high yields. Coordination of bispyridines with Zn2+ and Ag+ ions was observed by NMR and CD spectroscopy. The coordination ability of bis(2-pyridylethynyl) derivative 7 to palladium cation was determined by X-ray structure analysis.

Keywords: Sonogashira reaction; Alkynylations; Bispyridines; Binaphthalenes; C2-Symmetric ligands; Cross-coupling reactions; Palladium; Alkynes; Helicenes; Biaryls.

References: 43 live references.