Beyond 1,2,3-Triazoles: Formation and Applications of Ketenimines Derived from Copper Catalyzed Azide Alkyne Cycloaddition.

The ketenimines represent an interesting class of organic intermediates which has undergone a regrowth as a consequence of recent extensions of copper catalyzed azide alkyne cycloaddition (CuAAC) to other synthetic fields. This review summarizes the most recent generation methods of ketinimines from CuAAC reaction, highlighting chemical properties focused to the synthesis of cyclic compounds among others, affording a general outlook towards the development of new biologically active compounds.

Synthesis and Development of Indole Based 5-HT3 Receptor Antagonists as Anti-Emetic Drugs in Oncology: An Update.

An important group of antiemetic drugs used in the treatment of nausea and vomiting after chemotherapy containing an indole moiety in their structures, working as 5- hydroxytryptamine type 3 serotonin receptor antagonist (5-HT3). This study focuses on compounds bearing an indole core that present a 5-HT3 receptor antagonist activity, which have been successfully used as antiemetic drugs for reducing chemotherapy adverse secondary effects during cancer treatment. Their synthesis, biological activities, and some outstanding characteristics are discussed, providing a general outlook towards the development of more efficient antiemetic drugs.

Non-covalent interactions between sertraline stereoisomers and 2-hydroxypropyl-ß-cyclodextrin: a quantum chemistry analysis.

Inclusion compounds formed between sertraline stereoisomers and ß-cyclodextrin, and 2-hydroxypropyl-ß-cyclodextrin, were analyzed by using quantum chemistry methods. The exploration of the potential energy surface was performed using chemical intuition and classical molecular mechanics. This approach delivered around 200 candidates for low energy adducts, which were optimized through the PBE0/6-31G(d,p) method, and after this process solvent effects were considered by the continuous solvent model. This analysis showed that ß-cyclodextrin and 2-hydroxypropyl-ß-cyclodextrin are good trappers of sertraline, although the isomers suggested by molecular dynamics presented higher binding energies than those obtained by chemical intuition. The role of hydrogen bonds in the formation of adducts was studied using the non-covalent interactions index and the quantum theory of atoms in molecules. In this article we concluded that these interactions are present in all adducts, however, they are not important in the stabilization of these inclusion compounds. The molecular electrostatic potential indicates that Coulomb interactions could be responsible for the formation of these systems, although sophisticated solvent models must be used to confirm this conclusion, which are impractical in this case because of the sizes involved in these systems.

Hydrogen bonding capabilities of group 14 homologues of HCN and HNC.

This study is directed towards assessing hydrogen bond acceptor/donor capabilities of heavier group 14 homologues of HCN and HNC. A structural, energetic and topological study using ab initio (MP2, CCSD(T)), electrostatic potential (EP) and quantum theory of atoms in molecules (QTAIM) methodologies was carried out on HNX⋯HNX and HXN⋯HXN dimers and their respective monomers, where X = C, Si, Ge, Sn and Pb. The obtained results suggest the presence of weak hydrogen bonds in both kinds of complexes, and remarkably Ge and Sn act as unconventional hydrogen donors.

A facile synthesis of novel miconazole analogues and the evaluation of their antifungal activity.

Four novel miconazole analogues (8-11) were synthetized and evaluated for activity against four filamentous fungi (Mucor hiemalis, Aspergillus fumigatus, Trichosporon cutaneum, and Rhizopus oryzae) and eight species of Candida as yeast specimens. Compounds 9 and 10 showed very good activity when evaluated in yeast (MIC 0.112 and 0.163 µg/mL) compared to the reference compound, itraconazole (MIC 0.067 µg/mL). The best antifungal activity in filamentous strains was shown by compound 9. Hence compounds 9 and 10 represent new leads for further pharmacomodulation in this series.

Solvent effect in the polyethylene recovery from multilayer postconsumer aseptic packaging.

Polyethylene films were separated and recovered from polyethylene-aluminum composites derived from recycling multilayer postconsumer aseptic packaging. A brief study about the separation process by dissolving PE-aluminum (PE-Al) composites into a series of organic solvents with a combination of time and temperature is presented. Through this procedure, 56% polyethylene is recovered from this kind of composites in optimized conditions. DSC and TGA studies were performed to determine the thermal stability of recovered polyethylene films and to establish a comparison with a PE reference commercial product, demonstrating that recovered polyethylene films kept their thermal properties.

Alkyne-azide cycloaddition catalyzed by silver chloride and "abnormal" silver N-heterocyclic carbene complex.

A library of 1,2,3-triazoles was synthesized from diverse alkynes and azides using catalytic amounts of silver chloride instead of copper compounds. In addition, a novel "abnormal" silver N-heterocyclic carbene complex was tested as catalyst in this process. The results suggest that the reaction requires only 0.5% of silver complex, affording 1,2,3-triazoles in good yields.

Combination of perfluoroalkyl and triazole moieties: a new recovery strategy for TEMPO.

The attachment of multiple triazole moieties and perfluoroalkyl chains to TEMPO promotes emulsion formation in dichloromethane/water, giving a highly active and easily recoverable catalyst for the oxidation of alcohols.

Synthesis and application of phosphorus dendrimer immobilized azabis(oxazolines).

Phosphorus dendrimer immobilized azabis(oxazoline) ligands can be efficiently synthesized up to the third generation with 48 ligand molecules being attached to the periphery using click chemistry. The so-assembled macromolecules were evaluated in copper(II)-catalyzed asymmetric benzoylations, showing good yields and enantioselectivities. Moreover, the copper(II)-catalysts could be readily recovered and reused in several cycles. The globular structure of the dendritic ligands seems to prevent interference of the triazole moieties in the catalysis, contrasting MeOPEG or polystyrene bound ligands of the same type.