Tilman Lechel

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A three-component reaction with lithiated alkoxyallenes, nitriles, and perfluorinated carboxylic acids as precursors led to a series of perfluoroalkyl- or perfluoroaryl-substituted 4-hydroxypyridine derivatives. These compounds were converted into 4-pyridyl nonaflates which can be employed as versatile building blocks for the synthesis of pi-conjugated(More)
A series of trifluoromethyl-substituted 3-alkoxypyridinol derivatives has been deprotected to furnish pyridine-3,4-diol derivatives in good yields. The X-ray crystal structure analysis proved that a 1:1 mixture of pyridine-3,4-diols and their pyridin-4-one tautomers exist in the solid state. Subsequent conversion into bis(perfluoroalkanesulfonate)s were(More)
The flexible three-component reaction of lithiated alkoxyallenes with nitriles and carboxylic acids provided a series of highly functionalised beta-alkoxy-beta-ketoenamide derivatives. Upon base induced cyclisation and conversion to 4-pyridyl nonaflates various palladium-catalysed coupling reactions could be employed. The efficacy of this approach to(More)
Lithiated alkoxyallenes, nitriles, and carboxylic acids have been employed as precursors in a three-component reaction leading to highly substituted β-alkoxy-β-ketoenamides. Upon treatment with trifluoroacetic acid, these enamides could be easily cyclized to 5-acetyloxazole derivatives. The synthesis is very flexible with respect to the substitution pattern(More)
A mechanistically unique three-component synthesis provides a variety of functionalized pyridine derivatives in fair to excellent yields. The scope of this reaction was studied with respect to the alkoxyallene, the nitrile, and the carboxylic acid. Due to the 4-hydroxy group, these pyridine derivatives are suitable precursors for subsequent(More)
By a flexible three-component synthesis, alkoxy-substituted enamides are easily available from lithiated alkoxyallenes, nitriles and carboxylic acids (see scheme). The treatment of these versatile intermediates with trifluoroacetic acid provided 5-acetyloxazoles in moderate to good yields. Different substituents are possible at C-2 and C-5 and the 5-acetyl(More)
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