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Unprecedented Strong Lewis Bases—Synthesis and Methyl Cation Affinities of Dimethylamino‐Substituted Terpyridines
Author(s) -
Hommes Paul,
Fischer Christina,
Lindner Christoph,
Zipse Hendrik,
Reissig HansUlrich
Publication year - 2014
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201403403
Subject(s) - trifluoromethanesulfonate , trimethylsilyl trifluoromethanesulfonate , chemistry , lewis acids and bases , pyridine , acetylacetone , intramolecular force , affinities , trimethylsilyl , ketone , alkoxide , condensation , medicinal chemistry , stereochemistry , organic chemistry , catalysis , physics , thermodynamics
Abstract 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.