Search results for "PYRIDINE"
showing 10 items of 2516 documents
Recent Advances in the Synthesis of Piperidines: Functionalization of Preexisting Ring Systems
2018
Abstract The present review focuses on strategies for the construction of piperidines which have appeared in the literature since 2003 through mid-2017. In a preceding chapter ( 2017AHC191 ), we summarized synthetic methods involving the construction of the piperidine ring from essentially acyclic starting materials in an intra- or intermolecular manner. The present chapter aims at giving a general overview of decoration or modification of previously generated pyridines or piperidines. The hydrogenation of preformed pyridine or pyridinium rings and introduction of substituents into fully saturated piperidines as well as ring expansion of pyrrolidines to piperidines are the most prevalent me…
Targeting the Mitochondria by Novel Adamantane-Containing 1,4-Dihydropyridine Compounds
2012
Linda Klimaviciusa1, Maria A. S. Fernandes2, Nelda Lencberga1, Marta Pavasare1, Joaquim A. F. Vicente2, Antonio J. M. Moreno2, Maria S. Santos3, Catarina R. Oliveira4, Imanta Bruvere5, Egils Bisenieks5, Brigita Vigante5 and Vija Klusa1 1Department of Pharmacology, Faculty of Medicine, University of Latvia, Riga 2IMAR-CMA, Department of Life Sciences, University of Coimbra, Coimbra 3CNC, Department of Life Sciences, University of Coimbra, Coimbra 4CNC, Faculty of Medicine, University of Coimbra, Coimbra 5Laboratory of Membrane Active and beta-Diketone Compounds, Latvian Institute of Organic Synthesis, Riga 2,3,4Portugal 1,5Latvia
The Chemistry of the [1,2,3]Triazolo[1,5-a]pyridines: An Update
2010
Publisher Summary This chapter discusses the recent advancement in the chemistry of [1,2,3] triazolo[1,5-a]pyridines. It describes new discoveries in the physical properties and theoretical chemistry, focusing on synthesis of [1,2,3]triazolo[1,5-a]pyridine system, synthesis of novel aryltriazolopyridines, chiral ligands from [1,2,3]triazolo[1,5-a]pyridines, pyridylcarbene formation from triazolopyridines, ring-chain isomerization on [1,2,3]triazolo[1,5-a]pyridines, and novel pyridylcarbonylpyridines. All triazolopyridines have interesting ligand properties to form polynuclear complexes with different metal ions. X-ray single-crystal studies, magnetic, photo-magnetic, and colorimetric measur…
2-(3,5-Dimethyl-1H-pyrazol-1-yl)-2-hy-droxy-imino-N'-[1-(pyridin-2-yl)ethyl-idene]acetohydrazide.
2012
In the title compound, C14H16N6O2, the dihedral angles formed by the mean plane of the acetohydrazide group [maximum deviation 0.0629 (12) A] with the pyrazole and pyridine rings are 81.62 (6) and 38.38 (4)° respectively. In the crystal, molecules are connected by N—H⋯O and O—H⋯N hydrogen bonds into supramolecular chains extending parallel to the c-axis direction.
Transition metal ion induced hydrogelation by amino-terpyridine ligands
2014
Hydrogelation behavior of a new class of terpyridine based metallogelators are explored. The gelation and the gel morphology was found to be critically dependent on divalent metal ions, anions and on subtle structural changes on the gelator molecule.
Homocalixpyridines: Ligands Exhibiting High Selectivity in Extraction and Sensor Processes
1998
A novel spherical host architecture, based on pyridine subunits, has been created. It exhibits selective complexing properties toward soft metal ions (right), which have been tested in extraction and sensor processes. The complex-forming behaviour can be tailored by variation of the size of the cavity and by substitution. Homocalixpyridines are interesting in view of their application as selective carriers in separation and sensing techniques.
The reaction of enones with electrophiles
2010
Crystal Engineering Studies of the Complexes of Ethyl Resorcinarene with Aromatic Nitrogen Heterocycles
2003
Five X-ray structures of complexes of ethyl resorcinarene with aromatic nitrogen heterocycles (imidazole, 1,2,4-triazole, pyridine, pyrazine, 2-pyridylmethanol and quinoline) show that ethyl resorcinarene spontaneously forms molecular inclusion complexes with five- and six-membered aromatic nitrogen heterocycles via π π and CH π interactions. However, with 10-membered quinoline, no molecular inclusion complex is formed. Instead, quinoline manifests crystal lattice inclusion.
Highly Enantio- and Diastereoselective Inverse Electron Demand Hetero-Diels-Alder Reaction using 2-Alkenoylpyridine N-Oxides as Oxo-Heterodienes
2008
A general catalytic inverse electron demand hetero-Diels Alder reaction for 2-alkenoylpyridine N-oxides is presented. 2-Alkenoylpyridine N-oxides react very efficiently with alkenes in the presence of bisoxazolidine-copper(II) [BOX-Cu(II)] complexes to give chiral dihydropyrans bearing a pyridine ring at the 6-position with very high yields and excellent diastereo- and enantioselectivity. These heterodienes exhibited higher reactivity and enantioselectivity than the corresponding non-oxidized 2-alkenoylpyridines.
ChemInform Abstract: Triazolopyridines. Part 26. The Preparation of Novel [1,2,3]Triazolo[1,5-a]pyridine Sulfoxides.
2008
Abstract The regioselective synthesis of new triazolopyridine halides and sulfoxides with the substituent in all different ring positions of [1,2,3]triazolo[1,5- a ]pyridines is presented. The triazolo ring opening reaction of some representative sulfoxides to obtain disubstituted pyridines is also studied.