Activated enol ethers derived from esters or the dinitrile of malonic acid, or from pentane-2,4-dione were treated with hydrazine hydrate. The structures of the obtained products - pyrazoles 5 - were studied with a focus on tautomerism and supramolecular structure. A reverse addition of the reagents led to the isolation of two novel products, namely bis-enehydrazines 6 with an unsymmetrical arr...

3- or 4-Aroylfurans have been prepared selectively and in high yields from a common precursor by simple tuning of reaction conditions in Friedel-Crafts acylation promoted by triflic anhydride. The formation of products can be explained on the basis of the ring-chain tautomerism occurring in compounds equipped with two neighbouring carboxylic functions. Since 4-aroylfuran derivatives show a typi...

We theoretically investigate the mechanism of tautomerism in the gas-phase acetylacetone molecule. The minimum energy path between the enolone and diketo forms has been computed using the Nudged-Elastic Band (NEB) method within the density-functional theory (DFT) using the projector augmented-wave method and generalized gradient approximation in Perdew-Wang (PW91) parametrization. The lowest tr...

Tautomeric rearrangements on molecules lead to distinct equilibrated structural states of the same chemical compound, and evidently, have an impact on nearly all aspects of computer-aided chemical data processing [1] where the knowledge of the exact chemical structure is required (e.g. the calculation of chemical properties or interpretation of ligand-protein interactions). Although tautomerism...