A 100% atom-efficient thia-Michael addition process between thiols and α,β -unsaturated carbonyl compounds in a Brønsted acidic deep eutectic solvent at room temperature has been developed. The medium, choline chloride/p-toluene- sulfonic acid, not only showed good catalytic activity, but also could be readily recovered and reused with slight decrease in its activity after successive five runs.
Using ultrafast transient absorption spectroscopy, primary photophysical processes in aqueous and acetonitrile solutions of the trans,trans,trans-[Ptiv (N3)2(py)2(OH)2] complex, which is interesting as a potential light-activated anticancer drug, were investigated. A mechanism for early photoprocesses has been proposed, including ultrafast intersystem crossing and reductive dissociation.
It was established that the particle size of titanium oxide β-Ti3O5 has a great influence on the processes of phase formation and the stability of particles during heating. It was shown that at a temperature of about 456 K, β-Ti3O5 micro crystals undergo a reversible first-order phase transition, in which the low- temperature β-Ti3O5 phase is transformed into the high-temperature λ- Ti3O5 phase, and at higher temperatures the β-Ti3O5 phase is partially oxidized to form the Magnéli phase Ti4O7. It was found that β-Ti3O5 nanocrystals are unstable in an argon atmosphere and at temperatures above 400 K the β-Ti3O5 powder is oxidized.
A series of new 1’H-tetrazolo[1’,5’-c]-fused 3-aza-A- homosteroids were synthesized by azidation of progesterone, testosterone and hydrocortisone acetate in the presence of silicon tetrachloride. According to NMR spectroscopy and X-ray analysis, two double bond positional isomers (double bond in ring A or in ring B) are formed in various ratios; according to quantum chemical calculations, their energies are close within 0.4 kcal mol-1. Only low cytotoxic activity against Hep-2, MCF-7, HepG2, and Hek293 cell lines was determined in vitro for the compounds obtained.
Based on gas electron diffraction experiments supported by quantum chemical simulations, the molecular structure of 6-phenyl-1,5-diazabicyclo[3.1.0]hexane (PhDBH) in the gas phase was determined, which is characterized by the puckering motion of the five-membered ring typical of bicyclo[3.1.0]- hexanes. It was found that the previously determined crystal packing is accompanied by a certain torsional twisting of the molecule, requiring activation energy. Based on the simulations of PhDBH clusters, it was shown that the energy is compensated by intermolecular interactions.
Based on the processing of supramolecular environments of nitro group from Cambridge Structural Database by means of the ‘Atoms in Molecules’ analysis of promolecular electron density function, it is demonstrated that the topological stability of intermolecular bonding within one associate reflects trends in prevalence of interactions with particular geometry in real crystals.
New derivatives of dithiaazacrown ethers containing ψ-arylpyridine subunits were prepared based on the Hantzsch synthesis. The obtained compounds showed potential activities toward Hep-G2 cancer cell line, in both in silico and in vitro studies. The compounds were also good ligands for complex chemistry with metal ions due to possessing up to four heteroatoms and relatively big size of the crown ring.
A complex of mixed carboxylate pentafluorobenzoate (pfb) and phenylacetate (PhAc), viz. [Tb2(phen)2(pfb)2(PhAc)4] (phen is 1,10-phenanthroline), where each rare earth element (REE) ion is simultaneously coordinated to pentafluorobenzoic and phenylacetic acid anions, was for the first time synthesized and structurally characterized. To evaluate the influence of the second type of anion on the structure and photoluminescent properties, compounds with phenylacetic acid anions [Tb2(phen)2(PhAc)6] and pentafluorobenzoic acid anions [Tb2(EtOH)2(phen)2(pfb)6] were obtained. A change in the composition of the compounds from the phenylacetic acid anion to pentafluorobenzoate led to a change in the geometry of the metal scaffold and the REE polyhedron, a rearrangement of the system of non-covalent interactions according to the Hirshfeld surface analysis, and enhanced luminescence.
Intramolecular cyclization of adiponitrile with the formation of an amidinate functional group in zirconium coordination sphere was found. The obtained complex can be protolyzed with HCl in dioxane to afford a new representative of amidines, namely, 7-phenyl-1,3,4,5-tetrahydro-2H-azepin-2- imine in hydrochloride form.
The synthesis of homodimeric bis-esters of abiraterone (an inhibitor of androgens synthesis used for treatment of prostate cancer) as a novel depot form of the drug intended for parenteral administration has been undertaken. The conjugate with succinic linker has been synthesized, while only mono-esters of malic and citric acid were obtained. The target ‘twin’ demonstrated excellent characteristics in preliminary biotests, proving the concept of long-lasting depot-prodrug.
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：