Klaus Banert

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Several derivatives containing dihydronaphtho, naphtho[2,1-b]thiophene and thieno[2,3-d]pyrimidine ring systems were prepared starting from 2-amino-4,5-dihydronaphtho[2,1-b]thiophene-1-carbonitrile (1). Structure characterization of the thioxo derivative 7 was also performed and its reaction with some chloro and bromoalkyl reagents was studied. Moreover,(More)
Treatment of 5-amino-1-(9-methyl-5,6-dihydronaphtho[1',2':4,5]thieno[2,3-d]pyrimidin-11-yl)-1H-pyrazole-4-carbonitrile (1) with formic acid afforded pyrazolo[3,4-d]pyrimidin-4-one derivative 2. The sodium salt of the latter compound (generated in situ) was treated with some alkyl halides to afford the corresponding N-substituted compounds 3-7. The siloxy(More)
In this publication, a characterization of different azidoalkyne compounds using high-level ab initio quantum chemical methods is presented. For this purpose, the molecular structures and the 13C NMR chemical shifts have been calculated at the MP2 and CCSD(T) level of theory and the influence of zero-point vibration as well as the solvent on the chemical(More)
As a rule, acetylides and sulfonyl azides do not undergo electrophilic azide transfer because 1,2,3-triazoles are usually formed. We show now that treatment of tritylethyne with butyllithium followed by exposure to 2,4,6-triisopropylbenzenesulfonyl azide leads to products that are easily explained through the generation of short-lived tritylethynyl azide(More)
Azidoacetylene is a highly explosive substance, which has been synthesized and characterized for the first time quite recently [Banert et al., Angew. Chem., Int. Ed., 2012, 51, 7515]. As outlined in this work, the vibrational spectrum of azidoacetylene is dominated by strong couplings. For that reason, we have studied the vibrational spectrum of the title(More)
Synthesis of azido(trimethylsilyl)acetylene (6) was performed by treating the iodonium salt 5 with highly soluble hexadecyltributylphosphonium azide (QN₃) at -40 °C. Although this product is very unstable, it can nevertheless be trapped by the click reaction with cyclooctyne to give the corresponding 1,2,3-triazole, and also directly characterized by ¹H-(More)