Premium
Multifunctional “Clickates” as Versatile Extended Heteroaromatic Building Blocks: Efficient Synthesis via Click Chemistry, Conformational Preferences, and Metal Coordination
Author(s) -
Meudtner Robert M.,
Ostermeier Marc,
Goddard Richard,
Limberg Christian,
Hecht Stefan
Publication year - 2007
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200701240
Subject(s) - foldamer , chemistry , supramolecular chemistry , click chemistry , cycloaddition , aryl , combinatorial chemistry , ligand (biochemistry) , pyridine , triazole , coordination complex , stereochemistry , metal , crystallography , crystal structure , organic chemistry , catalysis , biochemistry , alkyl , receptor
Click chemistry has been utilized to access 2,6‐bis(1‐aryl‐1,2,3‐triazol‐4‐yl)pyridines (BTPs) as versatile extended heteroaromatic building blocks for their exploitation in supramolecular chemistry, in particular foldamer and ligand design. In addition to their high‐yielding synthesis using Cu I ‐catalyzed Huisgen‐type 1,3‐dipolar cycloaddition reactions the formed triazole moieties constitute an integral part of the BTP framework and encode both its pronounced conformational preferences as well as its chelating ability. A diverse set of symmetrical and non‐symmetrical BTPs carrying electron‐donating and ‐withdrawing substituents at both terminal aryl and the central pyridine moieties has efficiently been synthesized and could furthermore readily be postfunctionalized with amphiphilic side chains and porphyrin chromophores. In both solution and solid state, the BTP scaffold adopts a highly conserved horseshoe‐like anti–anti conformation. Upon protonation or metal coordination, the BTP scaffold switches to the chelating syn–syn conformation. Iron and europium complexes have been prepared, successfully characterized by single‐crystal X‐ray diffraction analysis, and investigated with regard to their spin state and luminescent properties. The extended heteroaromatic BTP scaffold should prove useful for the design of responsive foldamer backbones and the preparation of new magnetic and emissive materials.