Synthetic approaches to polypyridyl bridging ligands with proximal multidentate binding sites

Ruifa Zong; Dong Wang; Richard Hammitt; Randolph P Thummel

doi:10.1021/jo051937r

Synthetic approaches to polypyridyl bridging ligands with proximal multidentate binding sites

J Org Chem. 2006 Jan 6;71(1):167-75. doi: 10.1021/jo051937r.

Authors

Ruifa Zong¹, Dong Wang, Richard Hammitt, Randolph P Thummel

Affiliation

¹ Department of Chemistry, 136 Fleming Building, University of Houston, Houston, Texas 77204-5003, USA.

PMID: 16388632
DOI: 10.1021/jo051937r

Abstract

[reactions: see text] A series of 12 bridging ligands was prepared. These ligands include a central linker appended to two 1,8-naphthyrid-2-yl or two 1,10-phenanthrolin-2-yl units. The linkers include pyridazin-3,6-diyl, 1,8-naphthyrid-2,7-diyl, 2,2'-bipyrid-6,6'-diyl, 1,10-phenanthrolin-2,9-diyl, 1,2-di(2'-pyrid-6'-yl)ethyne, and 3,6-di(2'-pyrid-6'-yl)pyridazine. The ligands were synthesized from the diacetyl derivative of the central linker by a Friedländer condensation with either 2-aminonicotinaldehyde or 8-amino-7-quinolinecarbaldehyde. The precursor diacetyl derivatives were, in turn, prepared by pathways involving Stille and Sonogashira couplings. Examination of the electronic absorption spectra of the bridging ligands shows the strongest correlation to be between pairs of ligands having the same central linker. Complexation studies will follow.