Details

Autor(en) / Beteiligte

• Grosshenny, Vincent
• Romero, Francisco M
• Ziessel, Raymond

Titel

Construction of Preorganized Polytopic Ligands via Palladium-Promoted Cross-Coupling Reactions

Ist Teil von

• Journal of organic chemistry, 1997-03, Vol.62 (5), p.1491-1500

Ort / Verlag

American Chemical Society

Erscheinungsjahr

1997

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Rigid preorganized multitopic ligands have been designed and synthesized. The Pd(0)-catalyzed cross-coupling reactions between ethynylated derivatives of bipyridine or terpyridine and the corresponding bipyridine or terpyridine halides or triflates provide access to various homo-ditopic, hetero-ditopic, homo-tritopic, and hetero-tritopic ligands bearing acetylene or diphenylacetylene central units in fair to excellent yields. Optimal conditions were found with [Pd(PPh3)2Cl2], CuI in THF and diisopropylamine at rt, or with [Pd(PPh3)4] in benzene and diisopropylamine at 80 °C. When a phenylethynyl group is present in the molecule, the relevant conditions involve [Pd(PPh3)4] in n-propylamine at 60 °C. Oxidative dimerization of the ethynylated derivatives in the presence of cupric salts and oxygen gives the corresponding homo-ditopic ligands bearing diacetylene or diphenyldiacetylene as a spacer in good yields. These methods provide a practical approach to the rational design of multichelating ligands for coordination of redox and photoactive transition metals.