Search results for "medicinal"
showing 10 items of 2966 documents
Deprotonation of Fluoro Aromatics Using Lithium Magnesates.
2004
Abstract 3-Fluoropyridine was deprotonated on treatment with 1/3 equiv of Bu 3 MgLi in THF at −10 °C. The lithium arylmagnesate formed was either trapped with electrophiles or involved in a palladium-catalyzed cross-coupling reaction with 2-bromopyridine. The use of a less nucleophilic lithium-magnesium-dialkylamide, (TMP) 3 MgLi, allowed the reaction of 3-fluoroquinoline, giving the 2,2′-dimeric derivative. 2-Fluoropyridine and 2,6-difluoropyridine were deprotonated using 1/3 equiv of the highly coordinated magnesate Bu 4 MgLi 2 in THF at −10 °C in the presence of a substoichiometric amount of 2,2,6,6-tetramethylpiperidine. 1,3-Difluorobenzene reacted similarly when treated with Bu 3 MgLi;…
Aminoalkylbis(phenolate) [O,N,O] donor ligands for uranyl(VI) ion coordination: Syntheses, structures, and extraction studies
2007
Abstract The syntheses of five new aminoalkylbis(phenolate) ligands (as hydrochlorides) and their uranyl complexes are described. The reaction between uranyl nitrate hexahydrate and phenolic ligand [(N,N-bis(2-hydroxy-5-tert-butyl-3-methylbenzyl)-1-aminopropane) · HCl], H2L1 · HCl, forms a uranyl complex [UO2(HL1)2] · 2CH3CN (1). The ligand [(N,N-bis(2-hydroxy-5-tert-butyl-3-methylbenzyl)-1-aminobutane) · HCl], H2L2 · HCl, forms a uranyl complex with a formula [UO2(HL2)2] · 2CH3CN (2). The ligand [(N,N-bis(2-hydroxy-5-tert-butyl-3-methyl benzyl)-1-aminohexane) · HCl], H2L3 · HCl, yields a uranyl complex with a formula [UO2(HL3)2] · 2CH3CN (3) and the ligand [(N,N-bis(2-hydroxy-5-tert-butyl-…
Uranyl(VI) complexes with a diaminobisphenol from eugenol and N-(2-aminoethyl)morpholine: Syntheses, structures and extraction studies
2011
Abstract The syntheses and structural studies of an [O,N,O,N′]-type phenolic ligand [(N’,N’-bis(2-hydroxy-3-methoxy-5-(propen-2-yl)benzyl)-N-(2-aminoethyl)morpholine), (H2L) and two new uranyl complexes of this ligand are described. The reaction between uranyl nitrate hexahydrate and H2L in a 1:2 M ratio (M to H2L) results in a uranyl complex of the formula [UO2(HL)(NO3)(H2O)] (1). In the presence of a base (triethylamine), with the same molar ratio, the uranyl complex [UO2(HL)2]·2CH3CN (2) is formed. The molecular structures H2L, 1 and 2 were verified by X-ray crystallography. Both uranyl complexes are zwitterions with a neutral net charge. A comprehensive NMR-structural analyses of all co…
A theoretical study of the selectivity for the domino [5+2]/[4+2] cycloadditions of γ-pyrones bearing tethered alkenes with substituted 1,3-butadienes
2001
Abstract Selectivity of the domino [5+2]/[4+2] cycloaddition reactions of a β-silyloxy-γ-pyrone bearing a tethered alkene with two substituted 1,3-butadienes have been theoretically studied at the B3LYP/6-31G∗//AM1 and B3LYP/6-31G∗ computational levels. Analysis of these results allow explaining the regio, stereo and chemoselectivity observed experimentally at these domino reactions. Selectivity outcome is reproduced by these calculations.
ChemInform Abstract: A Theoretical Study of the Selectivity for the Domino [5 + 2]/[4 + 2] Cycloadditions of γ-Pyrones Bearing Tethered Alkenes with …
2010
Abstract Selectivity of the domino [5+2]/[4+2] cycloaddition reactions of a β-silyloxy-γ-pyrone bearing a tethered alkene with two substituted 1,3-butadienes have been theoretically studied at the B3LYP/6-31G∗//AM1 and B3LYP/6-31G∗ computational levels. Analysis of these results allow explaining the regio, stereo and chemoselectivity observed experimentally at these domino reactions. Selectivity outcome is reproduced by these calculations.
ChemInform Abstract: Phosphido- and Amidozirconocene Cation-Based Frustrated Lewis Pair Chemistry.
2016
Methyl abstraction from neutral [Cp2ZrMe(ERR′)] complexes 1 (E = N, P; R, R′ = alkyl, aryl) with either B(C6F5)3 or [Ph3C][B(C6F5)4] results in the formation of [Cp2Zr(ERR′)][X] complexes 2 (X– = MeB(C6F5)3–, B(C6F5)4–). The X-ray structure of amido complexes [Cp2Zr(NPh2)][MeB(C6F5)3] (2d) and [Cp2Zr(NtBuAr)][B(C6F5)4] (2e′, Ar = 3,5-C6H3(CH3)2) is reported, showing a sterically dependent Zr/N−π interaction. Complexes 2 catalyze the hydrogenation of electron-rich olefins and alkynes under mild conditions (room temperature, 1.5 bar H2). Complex 2e binds CO2, giving [Cp2Zr(CO2)(NtBuAr)]2[MeB(C6F5)3]2 (3e). Amido complex 2d reacts with benzaldehyde yielding [Cp2Zr(OCH2Ph)((OC)PhNPh2)][MeB(C6F5…
ChemInform Abstract: 1-Alkyl- and Azeto[1,2-a][1,5]benzodiazepine Derivatives in the Reaction of o-Phenylenediamine with 3-(Dimethylamino)propiopheno…
2001
The reaction of o-phenylenediamine (4) with one, two or three equivalents of p-substituted 3-dimethylaminopropiophenone hydrochlorides 5a−e was studied. 4-Aryl-2,3-dihydro-1H-1,5-benzodiazepine derivatives 6a−e were obtained in good yields, along with the 1:2-adducts 7c−e and the unexpected 1:3-adducts rac-8c−e. The type of adduct formed is determined by the molar ratio of the reactants 4 and 5 and by the nature of the substituent in the para position of the propiophenone 5.
Evidence of a 1,4-dipole intermediate in the reaction of 1-phenyl-4-vinylpyrazole with ptad
1985
Abstract 1-Phenyl-4-vinylpyrazole reacts with 1-phenyl-1,2,4-triazoline-3,5-dione in methylene chloride to form an unstable azetidine (4). An intermediate 1,4-dipole is probably involved since, when the reaction is conducted in acetone, a 1:1:1 adduct (3) is isolated.
Configurational effects in17O NMR chemical shifts of hydroxyl-substituted, bicyclo [2.2.1]heptenes and -heptanes, their methylated derivatives and so…
1993
Well resolved natural abundance 17O NMR spectra of 27 mono-, di-, tri- and tetrahydroxybicyclo[2.2.1]heptenes and -heptanes (norbornenes or norbornanes), their methylated derivatives and some related compounds were measured for 0.5 M or saturated solutions in acetonitrile at 65°C. In addition, the 17O NMR chemical shifts of 14 aliphatic and alicyclic alcohols were also determined for reference purposes. The 17O NMR chemical shifts of all compounds were assigned. Both methyl- and hydroxyl-induced deshielding β-effects were consistent with those reported in the literature. Similarly, observed shielding γ-effects were in agreement with the earlier observations and characteristic especially for…
Pentakis(dimethylzinn)diphosphid, struktur und kernresonanzspektren eines zinnreichen bicyclus
1979
Abstract Dehydrogenation of dimethylstannane combined with the hydrostannolysis of white phosphorus yields pentakis(dimethyltin) diphosphide, a tin-rich heterocyclic compound, which has the highly symmetric, bicyclic molecular structure of norbornane. Using the X-ray structure data the magnetic resonance spectra are discussed.