Synthesis of mono-, bis- and tris-tridentate ligands based on 5′-substituted-2,2′-bipyridine-6-carboxylic acid
作者:Loı̈c J Charbonnière、Nicolas Weibel、Raymond F Ziessel
DOI:10.1016/s0040-4039(00)02033-5
日期:2001.1
The synthesis of 5'-methyl-2,2'-bipyridine-6-carboxylic acid is described starting from the pivotal 5'-methyl-6-bromo-2,2'-bipyridine building block. Functionalisation of the latest at the 5'-methyl position gives access to the 5'-bromomethyl, 5'-hydroxymethyl and 5'-aminomethyl derivatives. Upon nucleophilic substitution, the hydroxy and amino derivatives react with the 5'-bromomethyl compound to give quasi-linear and podand type intermediates. Thanks to a carboalkoxylation reaction at the 6-bromo position of the different intermediates, followed by a saponification reaction, mono-, bis- and tris-tridentate ligands are obtained, which are particularly well suited for the complexation of lanthanide(III) cations. (C) 2001 Elsevier Science Ltd. All rights reserved.
5‘-Substituted-6-carboxylic-2,2‘-bipyridine Acid: A Pivotal Architecton for Building Preorganized Ligands
作者:Loïc J. Charbonnière、Nicolas Weibel、Raymond F. Ziessel
DOI:10.1021/jo0200015
日期:2002.5.1
A set of ligands bearing 6-bromo-2,2'-bipyridine pendant arms attached in the 5'-position are described. Trans formation of the bromo to an ester was performed by a carboethoxylation reaction promoted by low-valent Pd(0), while saponification followed by acidification gave the acids. The introduction of an appended function 3-nitrobenzyl, benzamidomethyl, and tert-butylacetyl opens the way to further functionalize these scaffolds for potential labeling of biological material. The synthetic protocols represent a valuable approach to the rational design of ligands bearing oxophilic and anionic sidearms.
Synthesis of Flexible Polydendate Ligands Bearing 5′-Substituted-6-carboxylic-2,2′-bipyridine Subunits
作者:Loïc J. Charbonnière、Nicolas Weibel、Raymond F. Ziessel
DOI:10.1055/s-2002-31968
日期:——
6-bromo-5'-bromomethyl-2,2'-bipyridine and acyclic amines or primary alcohol via base-assisted nucleophilic substitutions. In all cases, transformation of the bromo-function to the corresponding ethyl esters has been made possible under mild conditions using a palladium promoted carboethoxylation reaction, while saponification under basic conditions provided the corresponding acids after protonation. The utility of