- Method for synthesis of 3-piperidone derivatives through iridium catalytic hydrogenation
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A method for synthesis of 3-piperidone derivatives through iridium catalytic hydrogenation is provided, wherein a used catalyst is a triphenylphosphine complex of iridium. A reaction can be carried out under the following conditions: the temperature is 40-60 DEG C; the solvent is 1,2-dichloroethane; the pressure is 20-50 atmospheric pressures; the ratio of a substrate to a catalyst is 100 to 1; and the catalyst is a complex of chloro(1,5-cyclooctadiene)iridium(I) dimer and triphenylphosphine. Hydrogenation of 3-hydroxypyridine benzyl bromide salt can obtain the 3-piperidone derivatives with excellent chemoselectivity, the highest yield can reach 97%, and the chemical selectivity of ketones and alcohols is greater than 20:1. The method has the advantages of simple and convenient operation, easily obtained raw materials, high chemoselectivity, and good yield, and provides an atom economic and environment-friendly route for synthesis of a series of 3-piperidone derivatives.
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Paragraph 0037; 0038; 0039; 0054
(2016/10/08)
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- Iridium-catalyzed selective hydrogenation of 3-hydroxypyridinium salts: A facile synthesis of piperidin-3-ones
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The selective hydrogenation of 3-hydroxypyridinium salts has been achieved using a homogeneous iridium catalyst, providing a direct access to 2- and 4-substituted piperidin-3-one derivatives with high yields, which are important organic synthetic intermediates and the prevalent structural motifs in pharmaceutical agents. Mild reaction conditions, high chemoselectivity, and easy scalability make this reaction highly practical for the synthesis of piperidin-3-ones.
- Huang, Wen-Xue,Wu, Bo,Gao, Xiang,Chen, Mu-Wang,Wang, Baomin,Zhou, Yong-Gui
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supporting information
p. 1640 - 1643
(2015/04/14)
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- Convergent and selective synthesis of pyrrolidinones, piperidinones, dihydropyridinones and pyridinols from a common intermediate - Potential precursors of bioactive products
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Titanium-mediated cyclopropanation of natural and unnatural β-amino acid derivatives provides azabicyclo[3.1.0]hexan-1-ols as mixtures of diastereomers that are separable by silica-gel chromatography. Depending on the ring cleavage procedure employed, these compounds lead efficiently to diverse intermediates for the synthesis of pharmaceuticals. Thus, depending on the experimental conditions, basic treatment can furnish racemic pyrrolidinones as a mixture of diastereomers and piperidinones. In contrast, the synthesis of optically active dihydropyridinones was achieved through a one-pot FeCl 3/AcONa reaction or performed by using bis(sym-collidine)iodine hexafluorophosphate. Furthermore, whereas the palladium-mediated hydrogenolysis of these dihydropyridinones furnished both chiral piperidinones and original pyridinols, a CeIV-promoted radical process yielded chiral tricyclic piperidinones. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Jida, Mouhamad,Ollivier, Jean
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experimental part
p. 4041 - 4049
(2009/04/14)
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- Acid-catalyzed rearrangement of 1-benzyl-2-methyl-3-piperidone to 1-benzyl-2-acetylpyrrolidine
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We report that 1-benzyl-2-methyl-3-piperidone, conveniently prepared from 3-hydroxy-2-methylpyridine, undergoes rearrangement to 1-benzyl-2-acetylpyrrolidine in aqueous 6 N HCl at reflux. Studies showing that the 2,2-dimethyl analog is inert under the same conditions support a mechanism of reversible tautomeric equilibria via ring-opened intermediates, one of which was independently synthesized and shown to be a kinetically competent intermediate to product.
- Zhao, Shengyin,Jeon, Heung-Bae,Nadkarni, Durgesh V.,Sayre, Lawrence M.
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p. 6361 - 6369
(2007/10/03)
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- Synthesis and α-adrenergic activity of 2- and 6-methyl-substituted (3,4-dihydroxyphenyl)-3-piperidinols
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Previous drug-receptor interaction mechanism studies at the molecular level of adrenergic drugs made it possible to construct two three-dimensional molecular models, A and B, using conformationally restrained cyclic analogues of natural catecholamines, including 3-(3,4-dihydroxyphenyl)-3-piperidinol (3-DPP, 3); these models offer useful information about the steric requirements for the direct activation of α1- and α2-adrenergic receptors, respectively.In order to gain further knowledge about the steric requirements of these receptors, we also synthesized 3-(3,4-dihydroxyphenyl)-c-2-methyl-r-3-piperidinol (2-MDPP, 8) and the 3-(3,4-dihydroxyphenyl)-c- and -t-6-methyl-r-3-piperidinols (6-MDPPs 9 and 10); these differ from the 3-DPP 3 used for the construction of the molecular models exclusively in the presence of a methyl in the 2 or 6 position of the heterocyclic ring.The configuration and conformation of the MDPPs 8-10 were assigned by 1H-NMR and IR studies, and confirmed by conformational analysis performed by means of theoretical calculations.The α1- and α2-adrenergic properties were evaluated in vitro both by radioligand binding assays and by functional tests on isolated preparations.The results obtained made it possible to obtain a more refined steric definition of the A and B models. - Keywords: 3-piperidinol derivative; adrenergic α-stimulating activity; conformational analysis; molecular model.
- Macchia, B.,Macchia, M.,Martinelli, A.,Martinotti, E.,Orlandini, E.,et al.
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p. 231 - 240
(2007/10/03)
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- Iodide-promoted aldiminium ionalkyne cyclizations. A convenient synthesis of substituted tetrahydropyridines and 3-alkylidenepiperidines
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Iodide-promoted cyclizations of aldehydes with 4-alkynylamines and 3-alkynylamines provide direct synthetic access to alkylidenepiperidines 4 and tetrahydropyridines 8, respectively.
- Overman, Larry E.,Sarkar, Achintya K.
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p. 4103 - 4106
(2007/10/02)
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