Search results for " oxadiazole"

Synthesis of fluorinated oxadiazoles with gelation and oxygen storage ability

2012

A new family of fluorinated low molecular weight (LMW) gelators has been synthesized through SNAr substitution of 5-polyfluoroaryl-3-perfluoroheptyl-1,2,4-oxadiazoles with glycine ester. The obtained compounds give thermal and pH-sensitive hydrogels or thermo-reversible organogels in DMSO. Oxygen solubility studies showed the ability to maintain high oxygen levels in solution and in gel blend with plate counter agar (PCA).

Experimental and DFT Studies on Competitive Heterocyclic Rearrangements. A Cascade Isoxazole-1,2,4-Oxadiazole-Oxazole Rearrangement

2009

The thermal rearrangements of 3-acylamino-5-methylisoxazoles 1 have been investigated under basic and neutral conditions and interpreted with the support of computational data. The density functional theory (DFT) study on the competitive routes available for the base-catalyzed thermal rearrangement of isoxazoles 1 showed that the Boulton-Katritzky (BK) rearrangement, producing the less stable 3-acetonyl- 1,2,4-oxadiazoles 5, is a much more favored process than either the migration-nucleophilic attack-cyclization (MNAC) or the ring contraction-ring expansion (RCRE). In turn, an increase in reaction temperature will promote the MNAC of oxadiazoles 5, producing the more stable 2-acylaminooxazo…

1,2,4-Oxadiazole Topsentin Analogs with Antiproliferative Activity against Pancreatic Cancer Cells, Targeting GSK3β Kinase.

2021

A new series of topsentin analogs, in which the central imidazole ring of the natural lead was replaced by a 1,2,4- oxadiazole moiety, was efficiently synthesized. All derivatives were pre-screened for antiproliferative activity against the National Cancer Institute (NCI-60) cell lines panel. The five most potent compounds were further investigated in various pancreatic ductal adenocarcinoma (PDAC) cell lines, including SUIT-2, Capan-1, and Panc-1 cells, eliciting EC50 values in the micromolar and sub-micromolar range, associated with significant reduction of cell migration. These remarkable results might be explained by the effects of these new topsentin analogues on epithelial-to-mesenchy…

Molecular rearrangements of 1-oxa-2-azoles as an expedient route to fluorinated heterocyclic compounds

2005

Molecular rearrangements of O-N bond-containing azoles (1-oxa-2- azoles) represent a wide class of reactions by which various heterocycle-to- heterocycle transformations can be performed as alternative synthetic methodologies. The material presented in this review is an extensive survey of both thermal and photochemical methodologies that have been applied to fluorinated oxadiazoles, and shows how molecular rearrangements can be an alternative and in some cases the most convenient route for the synthesis of several fluorinated heterocycles.

Novel ANRORC rearrangements of 1,2,4-oxadiazoles

2010

Applications of ring rearrangements involving a participating side chain for the synthesis of five-membered heterocycles

2014

Synthesis of platinum complexes with 2-(5-perfluoroalkyl-1,2,4-oxadiazol-3yl)-pyridine and 2-(3-perfluoroalkyl-1-methyl-1,2,4-triazole-5yl)-pyridine …

2016

Five new mononuclear Pt(II) complexes with 5-perfluoroalkyl-1,2,4-oxadiazolyl-pyridine and 3-perfluoroalkyl-1,2,4-triazolyl-pyridine ligands are reported. The ligands 2-(5-perfluoroheptyl-1,2,4-oxadiazole-3yl)-pyridine (pfhop), 2-(5-perfluoropropyl)-1,2,4-oxadiazole-3yl)-pyridine (pfpop), 2-(3-perfluoroheptyl-1-methyl-1,2,4-triazole-5yl)-pyridine (pfhtp), 2-(3-perfluoropropyl-1-methyl-1,2,4-triazole-5yl)-pyridine (pfptp) and their complexes [PtCl2(pfhop)(2)]center dot 1.5 DMSO (2a), [PtCl2(pfpop)(2)]center dot 1.5 DMSO (3a), [PtCl2(pfhtp)(2)]center dot 1.5 DMSO (4a), PtCl2(pfhtp) (4b), [PtCl2(PfPtP)(2)]center dot 1.5 DMSO (5a) have been synthesized and structurally characterized. The comple…

Synthesis of novel 1,2,4-oxadiazole topsentin analogs with antitumor activity

2019

Synthesis of novel 1,2,4-oxadiazole topsentin analogs with antitumor activity

Tandem Reactions of 1,2,4-Oxadiazoles with Allylamines

2011

A reaction of 3-chloro-1,2,4-oxadiazoles with allylamine and diallylamine has been investigated. 3,3a,4,5-Tetrahydroisoxazolo[3,4-d]pyrimidines are produced through a tandem ANRORC/[3 + 2]cycloaddition pathway consisting of the addition of allylamine to the 1,2,4-oxadiazole, followed by ring opening, nitrone formation, and finally cycloaddition. 3-N-Allylamino-1,2,4-oxadiazoles were also obtained as minor products through a classical SNAr. Conversely, a reaction with diallylamine produces 3-N,N-diallylamino-1,2,4-oxadiazole and imidazoline through tandem SNAr/aziridination and nucleophilic ring opening.

Zn2+ and Cu2+ complexes of a fluorescent scorpiand-type oxadiazole azamacrocyclic ligand: crystal structures, solution studies and optical properties

2020

A ligand comprised of a macrocyclic pyridinophane core having a pendant arm containing a secondary amine group linked through a methylene spacer to a pyridyl–oxadiazole–phenyl (PyPD) fluorescent system has been prepared (L). The crystal structures of [ZnL](ClO4)2 and [CuL](ClO4)2 show that M2+ is coordinated to all the nitrogen atoms of the macrocyclic core, the secondary amine of the pendant arm and the nitrogen atom of the pyridine group of the fluorescent moiety, the latter bond being clearly weaker than the one with the pyridine of the macrocycle. Solution studies showed the formation of a highly stable Cu2+ complex with 1 : 1 stoichiometry, whereas with Zn2+ least stable complexes were…