Application of polyionic magnetic nanoparticles as a catalyst for the synthesis of carbonitriles with both indole and triazole moieties via a cooperative geminal-vinylogous anomeric-based oxidation

Three-component reaction of aldehydes with 3-(1H-indol-3-yl)-3-oxopropanenitrile and 1H-1,2,4-triazol-5-amine under the solvent-free condition at 70 °C was effectively performed in the presence of 2 mg of polyionic magnetic nanoparticles with pyrazine bridge [Fe₃O₄@SiO₂@(CH₂)₃]₂-Pyrazinium-[TCM]₂ as a catalyst for the synthesis of 7-aryl-5-(1H-indol-3-yl)-[1,2,4]triazolo[1,5-a]pyrimidine-6-carbonitriles via a cooperative anomeric-based oxidation. The polyionic magnetic nanoparticles catalyst was simply recovered and reused four successive runs. The morphology and structure of MNPs catalyst were investigated by numerous techniques such as XRD, FT-IR, EDX, WDX, FE-SEM, TEM, TGA, DTA, and VSM. The obtained products are reported for the first time that were identified by various analyses techniques such as melting point, FT-IR, ¹H NMR, ¹³C NMR, and elemental analysis (CHN). A term entitled a cooperative geminal-vinylogous anomeric-based oxidation was introduced for the latter step of the reaction mechanism for the first time. Synthesis of 7-aryl-5-(1H-indol-3-yl)-[1,2,4]triazolo[1,5-a]pyrimidine-6-carbonitriles by using [Fe₃O₄@SiO₂@(CH₂)₃]₂-Pyrazinium-[TCM]₂ MNPs as a catalyst.

Solvent-controlled metal coordination polymers of Co(ii) with different topological structures and properties

Three multidimensional Co-polymers were obtained. Co-1 exhibits as a 2D layer. Co-2 displays as a tetranodal (4,4,5,6)-connected 3D MOFs. Co-3 is a binodal (4,6)-connected 3D framework.

Open and closed forms of the interpenetrated [Cu2(Tae)(Bpa)2](NO3)2·nH2O: magnetic properties and high pressure CO2/CH4 gas sorption

Two closed and one open structural forms of the interpenetrated [Cu₂(Tae)(Bpa)₂](NO₃)₂·nH₂O (H₂Tae = 1,1,2,2-tetraacetylethane, Bpa = 1,2-bis(4-pyridyl)ethane) cationic coordination polymer have been synthesized. Three crystallographically related interpenetrated "ths" cationic nets encapsulate water molecules and nitrate anions giving rise to the closed structural forms of [Cu₂(Tae)(Bpa)₂](NO₃)₂·nH₂O. Depending on the location of water molecules and nitrate groups, two different closed forms with 5.5 and 3.6 crystallization water molecules have been obtained. The thermal activation of the closed structures gives rise to a 29% expansion of the unit cell. This closed to open transformation is reversible, and is triggered by the loss or uptake of solvent. The high pressure gas adsorption experiments show similar selectivity values towards CO₂ for CO₂/CH₄ mixtures to that showed by some metal organic frameworks without unsaturated metal sites, and isosteric heats for CO₂ adsorption similar to that for the HKUST-1 compound.

Strategies for overcoming tropical disease by ruthenium complexes with purine analog: Application against Leishmania spp. and Trypanosoma cruzi

Tropical diseases currently constitute a major health problem and thus a challenge in the field of drug discovery. The current treatments show serious disadvantages due to cost, toxicity, long therapy duration and resistance, and the use of metal complexes as chemotherapeutic agents against these ailments appears to be a very attractive alternative. Herein, we describe three newly synthesized ruthenium complexes with a bioactive molecule, the purine analogue 5,6,7-trimethyl-1,2,4-triazolo[1,5-a]pyrimidine (tmtp): cis,fac-[RuCl₂(dmso)₃(tmtp)] (1), mer-[RuCl₃(dmso)(H₂O)(tmtp)]·2H₂O (2) and fac,cis-[RuCl₃(H₂O)(tmtp)₂] (3). Their structures were characterized using X-ray and spectroscopic methods (IR, NMR or EPR). The stability of the synthesized complexes 1-3 in various buffered solutions (pH=3-7.4) was monitored using conventional and stopped-flow techniques. The in vitro antiproliferative activity of all ruthenium complexes against promastigote forms of Leishmania spp. (L. infantum, L. braziliensis, and L. donovani) and epimastigote forms of Trypanosoma cruzi was investigated. Notably, the results showed that the activity of 1 against L. brasiliensis was more than three-fold higher than that of glucantime, and 1 showed no appreciable toxicity towards J774.2 macrophages. Additionally, 2 displayed even 141-fold lower toxicity against host cells than glucantime, demonstrating significantly higher selectivity than the reference drug. Therefore, 1 and 2 appear to be excellent candidates for further development as potential drugs for the effective treatment of leishmaniasis and Chagas disease. All novel complexes were also shown to be potent inhibitors of Fe-SOD in the studied species, while their effects on human CuZn-SOD were very low.

Antiparasitic activity against trypanosomatid diseases and novel metal complexes derived from the first time characterized 5-phenyl-1,2,4-triazolo[1,5-a]pyrimidi-7(4H)-one

A serie of isostructural complexes with general formula [M(ftpO)₂(H₂O)₄] have been obtained from reaction between the first time characterized triazolopyrimidine derivative 5-phenyl-1,2,4-triazolo[1,5-a]pyrimidi-7(4H)-one (HftpO) (1) and first row transition nitrates (M=Cu (2), Co (3), Ni (4) and Zn (5)). A copper complex with formula [Cu(HftpO)₂(NO₃)₂(H₂O)₂]·H₂O (6) was also isolated. HftpO and their metal complexes have been characterized by spectroscopic and thermal analysis and their crystal structures have been solved by X-ray diffraction methods. The isostructural compounds are mononuclear complexes where the triazolopyrimidine ligand acts as monodentate ligand through N3 nitrogen position. The crystal structure of these novel bis-5-phenyl-1,2,4-triazolo[1,5-a]pyrimidin-7(4H)-one-tetraaquo metal complexes offers an excellent opportunity at these complexes to acts as potential building blocks. Also, the antiparasitic activity of HftpO ligand against different leishmania and trypanosome strains has been studied.

Experimental and theoretical investigation of the complexation of 5-methyl-7-isobutyl-1,2,4-triazolo[1,5-a]pyrimidine with platinum(ii) ions

Dichlorido platinum(ii) complexes with 5-methyl-7-isobutyl-1,2,4-triazolo[1,5-a]pyrimidine (ibmtp) were synthesized and characterized by various tools: IR, ¹H, ¹³C, ¹⁵N, ¹⁹⁵Pt NMR and DFT calculations.

Triazolopyrimidine compounds containing first-row transition metals and their activity against the neglected infectious Chagas disease and leishmaniasis

Leishmaniasis and Chagas disease remain a significant global problem. Current treatments have serious disadvantage due to cost, toxicity, long therapy duration and resistance. In the last years increasing interest has arisen in drug development to fight both diseases. Recently, metal-based drugs have revealed as promising drugs in a variety of therapeutic areas. Herein we describe six newly synthesized transition metal complexes with a bioactive molecule 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine (dmtp). All of them have been characterized by X-ray, spectroscopic and thermal methods. In vitro and in vivo studies (murine model) on the antiproliferative activity of these complexes against Leishmania spp. (Leishmania infantum, Leishmania braziliensis) and Trypanosoma cruzi have been carried out. Our results reveal a strong potential of three of the assayed compounds as antiparasitic agents against the above-mentioned infectious diseases.