Synthesis 2003(2): 0155-0184
DOI: 10.1055/s-2003-36811
REVIEW
© Georg Thieme Verlag Stuttgart · New York

Synthesis of 4′-Substituted-2,2′:6′,2′′-Terpyridines

Reza-Ali Fallahpour*
Rolic Research Ltd., Gewerbestrasse 18, 4123 Allschwil
Fax: +41(61)4872299; e-Mail: Reza.Fallahpour@rolic.ch;
Further Information

Publication History

Received 31 October 2002
Publication Date:
22 January 2003 (online)

Abstract

The terdentate ligand 2,2′:6′,2′′-terpyridine (tpy) has increasingly become one of the most popular ligands in coordination chemistry. A variety of substituents are utilised to tailor the properties of its metal complexes. 2,2′:6′,2′′-Terpyridine was reacted with almost all transition metals to form complexes. Among a series of tpy ligand derivatives, those containing substituents at the C(4′) position are of especial interest. Metal-bonded tpy ligands with spacers at C(4′) provide a means of directionality, and thus a means of linear communication, it means that electronic communication can occur along the coordination axis. In addition, the insertion of a single substituent at the C(4′)-position of the tpy ligand results in no enantiomeric derivatives, as the derivative retains its plane of symmetry. The synthetic strategies used to prepare tpy ligands are reviewed comprehensively.

  • 1 Introduction

  • 2 The Configuration of 2,2′:6′,2′′-Terpyridine

  • 3 Methods for the Synthesis of tpy Ligands

  • 3.1 Condensation Methodology

  • 3.2 Pyrolysis of Hydrazonium Salt

  • 3.3 Tohda Methodology

  • 3.4 Metal-mediated Methodologies

  • 3.5 Sauer Methodology

  • 4. Synthesis of Ligands

  • 4.1 4′-Aromatic Substituted-2,2′:6′,2′′-terpyridines

  • 4.2 Synthesis of tpy Ligands Possessing Functional Groups Directly Attached to C(4′)

  • 4.2.1 Preparation of Trimethyl Derivatives of 2,2′:6′,2′′-Terpyridine

  • 4.2.2 Carbonyl Derivatives of tpy Ligands

  • 4.2.3 Synthesis of 4′-Carbaldehyde Oxime-2,2′:6′,2′′-terpyridine

  • 4.2.4 Carboxylate Derivatives of tpy Ligands

  • 4.2.5 Synthesis of 4′-Nitro-2,2′:6′,2′′-Terpyridines

  • 4.2.6 Synthesis of 4′-Hydroxy-2,2′:6′,2′′-terpyridines

  • 4.2.7 Synthesis of 4′,4′-Bis(2,2′:6′,2′′-terpyridyl)amine

  • 4.2.8 Synthesis of 4′-Thio-substituted 2,2′:6′,2′′-Terpyridines

  • 4.2.9 Synthesis of 2,2′:6′,2′′-Terpyridine-1′-oxides

  • 5 Conclusion

237

Fallahpour R.-A. unpublished results.