Search results for "Pyridine-N-oxide"

showing 10 items of 19 documents

Bis(oxazoline) Lewis Acid Catalyzed Aldol Reactions of PyridineN-Oxide Aldehydes—Synthesis of Optically Active 2-(1-Hydroxyalkyl)pyridine Derivatives…

2006

A new, short, and simplified procedure for the synthesis of optically active pyridine derivatives from pro-chiral pyridine-N-oxides is presented. The catalytic and asymmetric Mukaiyama aldol reaction between ketene silyl acetals and 1-oxypyridine-2-carbaldehyde derivatives catalyzed by chiral copper(II)-bis(oxazoline) complexes gave optically active 2-(hydroxyalkyl)- and 2-(anti-1,2-dihydroxyalkyl)pyridine derivatives in good yields and diastereoselectivities, and in excellent enantioselectivities-up to 99 % enantiomeric excess. As a synthetic application of the developed method, a full account for the asymmetric total synthesis of a nonnatural indolizine alkaloid is provided.

AldehydesOptics and PhotonicsPyridinesChemistryOrganic ChemistryIndolizinesEnantioselective synthesisTotal synthesisPyridine-N-oxideStereoisomerismGeneral ChemistryOxazolineCatalysisCyclic N-OxidesChemistrychemistry.chemical_compoundAlkaloidsAldol reactionPyridineOrganic chemistryIndolizineEnantiomeric excessAcidsChemistry - A European Journal
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2-(Mesitylmethylsulfanyl)pyridine N-oxide monohydrate

2008

In the title compound, C15H17NOS·H2O, the benzene and pyridine rings form a dihedral angle of 71.18 (2)°. The intramolecular S...O distance [2.737 (3) Å] is shorter than expected and, in terms of hybridization principles, the N—C—S angle [114.1 (2)°] is smaller than expected. The crystal structure is stabilized by intermolecular O—H...O and weak C—H...O hydrogen bonds. In addition, weak π–π stacking interactions with a centroid–centroid distance of 3.778 (3) Å are also observed.

ChemistryHydrogen bondStackingPyridine-N-oxideGeneral ChemistryCrystal structureDihedral angleCondensed Matter PhysicsBioinformaticsOrganic Paperslcsh:Chemistrychemistry.chemical_compoundCrystallographylcsh:QD1-999PyridineGeneral Materials ScienceBenzeneActa Crystallographica Section E
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2-(Benzylsulfanyl)pyridineN-oxide

2008

In the title compound, C12H11NOS, the dihedral angle between the oxopyridinium and phenyl rings is 58.40 (1)°. The crystal structure is stabilized by C—H...O hydrogen bonds, π–π stacking interactions involving the pyridinium rings [centroid–centroid distance = 3.6891 (9) Å] and C—H...π interactions.

CrystallographyHydrogen bondStackingPyridine-N-oxideGeneral ChemistryCrystal structureDihedral angleCondensed Matter Physicscomputer.software_genreOrganic Paperschemistry.chemical_compoundCrystallographychemistryQD901-999General Materials SciencePyridiniumData miningcomputerActa Crystallographica Section E Structure Reports Online
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2-(2,3,5,6-Tetra­methyl­benzyl­sulfan­yl)pyridine N-oxide

2008

In the title compound, C16H19NOS, the durene ring and the oxopyridyl ring form a dihedral angle of 82.26 (7)°. The crystal structure is stabilized by intermolecular C—H...O hydrogen bonds, weak C—H...π interactions and π–π interactions [centroid–centroid distance of 3.4432 (19) Å], together with intramolecular S...O [2.657 (2) Å] short contacts.

CrystallographybiologyHydrogen bondDurenePyridine-N-oxideGeneral ChemistryCrystal structureDihedral angleCondensed Matter PhysicsBioinformaticsbiology.organism_classificationRing (chemistry)Organic PapersCrystallographychemistry.chemical_compoundchemistryQD901-999TetraGeneral Materials ScienceActa Crystallographica Section E: Structure Reports Online
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Strong N−X⋅⋅⋅O−N Halogen Bonds: A Comprehensive Study on N‐Halosaccharin Pyridine N ‐Oxide Complexes

2019

A study of the strong N-X⋅⋅⋅- O-N+ (X=I, Br) halogen bonding interactions reports 2×27 donor×acceptor complexes of N-halosaccharins and pyridine N-oxides (PyNO). DFT calculations were used to investigate the X⋅⋅⋅O halogen bond (XB) interaction energies in 54 complexes. A simplified computationally fast electrostatic model was developed for predicting the X⋅⋅⋅O XBs. The XB interaction energies vary from -47.5 to -120.3 kJ mol-1 ; the strongest N-I⋅⋅⋅- O-N+ XBs approaching those of 3-center-4-electron [N-I-N]+ halogen-bonded systems (ca. 160 kJ mol-1 ). 1 H NMR association constants (KXB ) determined in CDCl3 and [D6 ]acetone vary from 2.0×100 to >108  m-1 and correlate well with the calculat…

Halogen bond010405 organic chemistryPyridine-N-oxideGeneral MedicineGeneral ChemistryCrystal structure010402 general chemistry01 natural sciencesCatalysis0104 chemical sciencesCrystallographychemistry.chemical_compoundchemistryHalogenPyridineAcetoneElectrostatic modelAngewandte Chemie International Edition
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Methylresorcinarene: a reaction vessel to control the coordination geometry of copper(II) in pyridine N-oxide copper(II) complexes

2015

Pyridine and 2-picolinic acid N-oxides form 2 : 2 and 2 : 1 ligand : metal (L : M) discrete L2M2 and polymeric complexes with CuCl2 and Cu(NO3)2, respectively, with copper(ii) salts. The N-oxides also form 1 : 1 host-guest complexes with methylresorcinarene. In combination, the three components form a unique 2 : 2 : 1 host-ligand-metal complex. The methylresorcinarene acts as a reaction vessel/protecting group to control the coordination of copper(ii) from cis-see-saw to trans-square planar, and from octahedral to square planar coordination geometry. These processes were studied in solution and in the solid state via(1)H NMR spectroscopy and single crystal X-ray diffraction.

Magnetic Resonance SpectroscopyPyridinesmethylresorcinareneInorganic chemistrychemistry.chemical_elementPyridine-N-oxideNuclear magnetic resonance spectroscopyCopperInorganic Chemistrychemistry.chemical_compoundCrystallographychemistryOctahedronX-Ray DiffractionCoordination ComplexesPyridinecopper complexesCalixarenesProtecting groupSingle crystalta116CopperCoordination geometryDalton Transactions
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catena-Poly[[aquasodium(I)]-μ-[2,2′-(disulfanediyl)bis(pyridineN-oxide)]-μ-(pyridine-2-thiolato 1-oxide)]

2009

There are two monomeric units in the asymmetric unit of the polymeric title compound, [Na(C(5)H(4)NOS)(C(10)H(8)N(2)O(2)S(2))(H(2)O)](n). The Na(I) ions are six coordinated by four O atoms, one S atom and one water mol-ecule, forming a slightly distorted octa-hedral geometry. An intra-molecular O-H⋯O hydrogen bond stabilizes the conformation of the mol-ecule. The crystal packing is consolidated by inter-molecular O-H⋯O, O-H⋯N and O-H⋯S hydrogen bonds, π-π inter-actions [with centroid-centroid distances of 3.587 (2) Å] together with weak C-H⋯π inter-actions. The mol-ecules are linked into polymeric chains along the b-axis direction.

Metal-Organic Paperschemistry.chemical_classificationHydrogen bondOxidePyridine-N-oxideGeneral ChemistryCondensed Matter PhysicsBioinformaticsIonCrystalchemistry.chemical_compoundCrystallographyMonomerchemistryPyridineThiolGeneral Materials ScienceActa Crystallographica Section E Structure Reports Online
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Conformational changes in Cmethyl-resorcinarene pyridine N -oxide inclusion complexes in the solid state

2016

Aromatic N-oxides interact with Cmethyl-resorcinarene resulting in marked changes in the conformation of the host resorcinarene. In the solid state, 2- and 3-methylpyridine N-oxides form pseudo-capsular 2 : 2 endo host-guest complexes with Cmethyl-resorcinarene stabilized by C-H⋯π interactions. The Cmethyl-resorcinarene·2-methylpyridine N-oxide complex has a C4v crown conformation, while the Cmethyl-resorcinarene·3-methylpyridine N-oxide complex has a slightly open C2v boat conformation. On the contrary, other para-substituted and benzo-fused pyridine N-oxides form only exo complexes with Cmethyl-resorcinarene. In the exo complexes, the asymmetry of the guest, conformational flexibility and…

N-oxidesHydrogenta114010405 organic chemistryChemistryStereochemistryHydrogen bondCyclohexane conformationSolid-statechemistry.chemical_elementPyridine-N-oxidemacromolecular substancesGeneral ChemistryResorcinarene010402 general chemistryCondensed Matter Physics01 natural sciences0104 chemical sciencesCrystallographychemistry.chemical_compoundPyridineGeneral Materials ScienceN-oxide inclusion complexesta116CRYSTENGCOMM
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Structure of the copper (II) perchlorate complex with Schiff base ligand containing pyridine N-oxide fragments and propylene bridges: Solvatochromic …

2005

Abstract The copper (II) perchlorate complexes with Schiff base ligands were investigated by X-ray single crystal analysis, electron spectroscopy, infrared and electron paramagnetic spectroscopy. The Schiff bases were obtained as condensation products of 2-pyridinecarboxaldehyde N-oxide with dipropylenetriamine (L1) and triethylenetetramine (L3), respectively. The structure of the complex [CuL2](ClO4)2 was solved. In the structure, the ligand exists in the form of aliphatic polyamine containing two Schiff bases in contrary to the free form of this ligand with one pyrimidine ring and one Schiff base. Electronic spectra of the copper (II) perchlorate complexes of both ligands in different sol…

Schiff baseCopper(II) perchlorateChemistryLigandPyridine-N-oxidechemistry.chemical_elementPhotochemistryElectron spectroscopyCopperInorganic Chemistrychemistry.chemical_compoundPerchlorateTriethylenetetraminePolymer chemistryMaterials ChemistryPhysical and Theoretical ChemistryPolyhedron
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CCDC 666243: Experimental Crystal Structure Determination

2008

Related Article: B.R.D.Nayagam, S.R.Jebas, S.Grace, D.Schollmeyer|2008|Acta Crystallogr.,Sect.E:Struct.Rep.Online|64|o409|doi:10.1107/S1600536807068766

Space GroupCrystallography22'-(2356-Tetramethyl-p-phenylene-bis(methylenethio))-bis(pyridine-N-oxide)Crystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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