Novel Thiourea Ligands-Synthesis, Characterization and Preliminary Study on Their Coordination Abilities.

Two series of polydentate ,,-ligands containing thiourea fragments attached to a -cresol scaffold, unsymmetrical mono-acylated bis-amines and symmetrical bis-thioureas, are obtained by common experiments. It is observed that the reaction output is strongly dependent on both bis-amine and thiocarbamic chloride substituents. The products are characterized by 1D and 2D NMR spectra in solution and by single crystal XRD.

Functionalization of 2-Mercapto-5-methyl-1,3,4-thiadiazole: 2-(ω-Haloalkylthio) Thiadiazoles vs. Symmetrical Bis-Thiadiazoles.

A study on the functionalisation of 2-mercapto-5-methyl-1,3,4-thiadiazole has been conducted, yielding two series of products: 2-(ω-haloalkylthio)thiadiazoles and symmetrical bis-thiadiazoles, with variable chain lengths. The experimental conditions were optimised for each class of compounds by altering the base used and the reagents' proportions, leading to the development of separate protocols tailored to their specific reactivity and purification needs. The target halogenide reagents and bis-thiadiazole ligands were obtained either as single products or as mixtures easily separable by chromatography.

Polydentate ,-Ligands Possessing Unsymmetrical Urea Fragments Attached to a -Cresol Scaffold.

In this study, three series of polydentate ,-ligands possessing unsymmetrical urea fragments attached to a -cresol scaffold are obtained, namely mono- and bi-substituted open-chain aromatics, synthesised using a common experiment, as well as fused aryloxazinones. Separate protocols for the preparation of each series are developed. It is found that in the case of open-chain compounds, the reaction output is strongly dependent on both bis-amine and carbamoyl chloride substituents, while oxazinones can be effectively obtained via a common protocol.

Spontaneous conversion of -tosylates of 2-(piperazin-1-yl)ethanols into chlorides during classical tosylation procedure.

A direct conversion of piperazinyl ethanols into chlorides via a classical -tosylation protocol is observed. The acceleration of the transformation by the piperazine unit is demonstrated. It is found that the reaction goes via the corresponding -tosylate, which converts spontaneously into chloride with different rate depending on the substrate structure.

Synthesis of Chiral Cyclopentenones.

The cyclopentenone unit is a very powerful synthon for the synthesis of a variety of bioactive target molecules. This is due to the broad diversity of chemical modifications available for the enone structural motif. In particular, chiral cyclopentenones are important precursors in the asymmetric synthesis of target chiral molecules.

Tautomerism of 4,4'-dihydroxy-1,1'-naphthaldazine studied by experimental and theoretical methods.

Background: The title compound belongs to the class of bis-azomethine pigments. On the basis of comparative studies on similar structures, insight into the complex excited state dynamics of such compounds has been gained. It has been shown, for example, that only compounds that possess hydroxyl groups are fluorescent, and that the possibility for cis-trans isomerisation and/or bending motions of the central bis-azomethine fragment allows for different non-radiative decay pathways.

Simple transformation of crystalline chiral natural anions to liquid medium and their use to induce chirality.

New chiral ionic liquids can be prepared simply by combining the tetra-n-hexyl-dimethylguanidinium cation with readily available chiral anions and used as an asymmetric inducing agent as demonstrated for catalytic Rh(II) carbenoid C-H insertion and Sharpless dihydroxylation.

Microwave accelerated facile synthesis of fused polynuclear hydrocarbons in dry media by intramolecular Friedel-Crafts alkylation.

Fused polynuclear tetrahydro arenes are synthesised in a fast, simple, high yielding and regiospecific procedure by an intramolecular Friedel-Crafts alkylation in dry media under microwave irradiation of the corresponding 1-bromo-4-arylbutanes immobilised on silica. The observed reactivity is rationalised by molecular modelling studies which suggest the occurrence of a concerted mechanism.