%0 journal article
%@ 1433-7851
%A Hommes, P.,Fischer, C.,Lindner, C.,Zipse, H.,Reissig, H.

%D 2014
%J Angewandte Chemie - International Edition
%N 29
%P 7347-7651 
%R doi:10.1002/anie.201403403
%T Unprecedented Strong Lewis Bases - Synthesis and Methyl Cation Affinities of Dimethylamino-Substituted Terpyridines†
%U https://doi.org/10.1002/anie.201403403
29 
%X A versatile method for the synthesis of functionalized 2,2′:6′,2′′-terpyridines by assembly of the terminal pyridine rings is presented. The cyclization precursors—bis-β-ketoenamides—are prepared from 4-substituted 2,6-pyridinedicarboxylic acids and acetylacetone or its corresponding enamino ketone. Treatment with trimethylsilyl trifluoromethanesulfonate induces a twofold intramolecular condensation providing an efficient access to 4,4′′-di- and 4,4′,4′′-trifunctionalized 6,6′′-dimethyl-2,2′:6′,2′′-terpyridines. Using this method, hitherto unknown 4,4′′-bis(dimethylamino)- and 4,4′,4′′-tris(dimethylamino)terpyridines have been prepared that show remarkably high calculated Lewis basicities.