Search results for "Piperidine"
showing 10 items of 236 documents
Stereoselective Synthesis of 3-Substituted and 3,4-Disubstituted Piperidine und Piperidin-2-one Derivatives
2012
The stereoselective synthesis of 3-substituted and 3,4-disubstituted piperidine and piperidin-2-one derivatives was achieved starting from 2-pyridone. After N-galactosylation and subsequent O-silylation, nucleophilic addition of organometallic reagents proceeded with high regio- and stereoselectivity at 4-position. Substituents at position 3 were stereoselectively introduced by reaction of electrophiles with amide enolates of the N-galactosyl-2-piperidones.
Stereoselective Synthesis of Enantiomerically Pure Piperidine Derivatives by N-Galactosylation of Pyridones.
2004
Stereoselective desymmetrization of 4-pyridone has been achieved through selective N-galactosylation, activation of the N-(galactosyl)pyridone by O-silylation and immediate addition of Grignard compounds. Chiral piperidine derivatives, e.g. (S)-(+)-coniine and (5S,9S)-(+)-indolozidine 167B, were synthesised in enantiomerically pure form using these highly regio- and stereoselective reactions. After N-galactosylation of 2-pyridone and O-silylation of the N-galactosyl-2-pyridone, addition of a Grignard compound proceeded with high 1,4-regioselectivity and complete diastereoselectivity, to furnish 4-substituted 5,6-dehydro-2-piperidones. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Ger…
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…
1967
Enamines derived from cyclic ketones behave as difunctional intermediates when treated with phenyl isocyanate to produce dicarboxanilides. Reaction of bis(4-isocyanatophenyl)-methane with 1-N-morpholino-1-cyclopentene in DMSO leads to poly[iminocarbonyl(2-morpholino-1-cyclopenten-1.3-ylene)carbonylimino-p-phenylenemethylene-p-phenylene], a polyamide. The effects of various cyclic enamines and diisocyanates on the polymerization are surveyed. Morpholine and piperidine are more effective than pyrrolidine or dimethylamine when incorporated into cyclopentanone enamines. The molecular weight of the polymer decreases when the ring size of the ketone component is increased. The efficiency of the d…
Mononuclear heterocyclic rearrangements 5. Kinetic Investigation of the behaviour of (e)- and (z)-phenylhydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadia…
1980
The kinetic behaviour of the geometrical isomers I-E and I-Z of the title compound in the presence of piperidine in benzene has been investigated. The kinetic results suggest that I-Z rearranges directly into 2,5-diphenyl-4-benzoylamino-1,2,3-triazole (II), whereas I-E probably rearranges only through the intermediate I-Z formed by isomerization. All the reactions studied are piperidine-catalyzed.
Mononuclear heterocyclic rearrangement. Part 6 . Studies on base catalysis of the rearrangement of the (Z)-p-nitrophenylhydrazone of 3-benzoyl-5-phen…
1981
Stereoselective Syntheses of Piperidine-Containing Heterocycles Using Carbohydrate Auxiliaries
2003
CCDC 1573804: Experimental Crystal Structure Determination
2017
Related Article: Paul J. Ragogna, Cameron Graham, Clement Millet, Amy N Price, Juuso Valijus, Michael J Cowley, Heikki Tuononen|2017|Chem.-Eur.J.|24|672|doi:10.1002/chem.201704337
Crystal structure and Hirshfeld surface analysis of 3-octyl-4-oxo-2,6-bis(3,4,5-trimethoxyphenyl)piperidinium chloride
2018
The title compound was synthesized by a one-pot Mannich condensation reaction. In the crystal, centrosymmetric dimers are linked into layers parallel to (011) by N—H⋯Cl and C—H⋯Cl hydrogen bonds. A Hirshfeld surface analysis indicates that O—H (20.5%) interactions make the largest contribution to the crystal packing.
Crystal structure of chlorido-{4,5-dimeth-oxy-2-[(2,3-η)-2-prop-2-en-1-yl]phenyl-κC (1)}(piperidine-κN)platinum(II) ethanol monosolvate
2014
The title platinum(II) complex shows a trigonal–bipyramidal coordination and intermolecular C—H⋯Cl, C—H⋯π and (C/O)—H⋯O hydrogen bonds.