Biomedical subjects

Andrea Arany

Publications and source records attributed to Andrea Arany.

3 recordsLinked to original sources

PubMed2004

Highly-functionalised difluorinated (hydroxymethyl)conduritol analogues via the Diels-Alder reactions of a difluorinated dienophile.

A difluorodienophile, synthesised using a Stille coupling reaction underwent tin(iv)-catalysed cycloaddition with three furans to afford oxa[2.2.1]bicycloheptenes in good yield. Reduction of ester and carbamate carbonyl groups and diol protection as the acetonide set the stage for palladium-catalysed hydrostannylation in two cases. Treatment of the stannanes with methyllithium triggered ring-opening to afford highly-functionalised difluorinated cyclohexenols which could be deprotected to afford (hydroxymethyl)conduritol analogues.

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PubMed2003

DOTTADs--readily made novel metal ligands with multivariant functionality--trans-DOTTADs and semi-DOTTADs.

Two new ligand systems related to the previously described DOTTADs have been generated in a simple one step reaction. The first, trans-DOTTADs, were formed by Vilsmeier formylation (followed by cyclisation and N-demethylation) of 2,6-dimethyl-3,5-pyrazine-dicarboxylic acid, to give the novel bis-pyridinopyrazine dialdehyde ligands. The corresponding pyrazine diester, reacted similarly to an intermediate iminium ion stage, which gave trans-DOTTAD imines on work-up with amines. The treatment of Hantzsch ester with two equivalents of benzaldehyde gave 7-phenyl-2-(2-phenylethenyl)-7,8-dihydropyrano[4,3-b]pyridin-5-one-3-carboxylic acid. This product underwent similar cyclisation with Vilsmeier reagents to give, for example, 6-methyl-2-(2-phenylethenyl)-8-(phenylhydroxymethyl)-6H-[1,6]naphthyridin-5-one-3-carboxylic acid, an example of a semi-DOTTAD.

Journal Article↗

PubMed2003

DOTTADs--readily made novel metal ligands with multivariant functionality.

The interaction of Hantzsch pyridinecarboxylic acids with dialkylformamides and POCl3, followed by treatment with NH4OH yields 1,8-dioxo-1,2,7,8-tetrahydro-2,7,10-triazaanthracenes (DOTTADs), which have great potential as useful ligands for Group I and II metals and some transition metals. The corresponding Hantszch esters similarly for DOTTADs or their bis-imines by way of isolable intermediates, which are then treated with an amine RNH2. DOTTAD-imines are also available from DOTTADs with amines and this reaction is also effective with 1,8-diamino-3,6-dioxaoctane to give macrocyclic analogues, as well as with chiral amines. DOTTAD-imines can be reduced with diethylsilane and Wilkinson's catalyst to the corresponding amines, which can also be formed from DOTTADs by reductive amination with amines and Na(AcO)3BH. Mono-aldols of DOTTADs are easily formed by treatment of DOTTADs with acetone.

Journal Article↗