- Selective hydrogenation of paracetamol to acetamidocyclohexanone with silylated SiO2 supported Pd-based catalysts
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A series of catalysts comprising well-distributed Pd nanoparticles incorporated on silylated SiO2 were fabricated by the wet impregnation method and investigated in the selective hydrogenation of paracetamol to 4-acetamidocyclohexanone. The catalysts calcined at different temperatures were characterized by TG, FT-IR, N2 physisorption, TPR and XPS. The results showed that organic modification led to a catalyst surface composed of stable Si-(CH3)3 species even after calcination at 300 °C. Also, changes occurred in the size and electronic properties of the Pd particles through the different amounts of grafted groups on the SiO2 support. The mode of adsorption of the paracetamol molecule was influenced by the quite bulky organic groups on the support, resulting in a significant improvement in selectivity towards 4-acetamidocyclohexanone and preventing full hydrogenation to some extent. The best result was obtained on the silylated Pd catalyst calcined at 500 °C, with 64.9% selectivity to keto at the paracetamol conversion of 60.5%, while the non-silylated SiO2 supported Pd catalyst gave 4-acetamidocyclohexanone selectivity of 29.1% at 53.8% conversion.
- Song, Wenjing,Liu, Xiuna,Jiang, Shaoyang,Chen, Zhou,Weng, Weizheng,Rodríguez-Ramos,Yi, Xiaodong,Fang, Weiping
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- Catalytic Transfer Hydrogenation of Arenes and Heteroarenes
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Transfer hydrogenation reactions are of great interest to reduce diverse molecules under mild reaction conditions. To date, this type of reaction has only been successfully applied to alkenes, alkynes and polarized unsaturated compounds such as ketones, imines, pyridines, etc. The reduction of benzene derivatives by transfer hydrogenation has never been described, which is likely due to the high energy barrier required to dearomatize these compounds. In this context, we have developed a catalytic transfer hydrogenation reaction for the reduction of benzene derivatives and heteroarenes to form complex 3-dimensional scaffolds bearing various functional groups at room temperature without needing compressed hydrogen gas.
- Gelis, Coralie,Heusler, Arne,Nairoukh, Zackaria,Glorius, Frank
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supporting information
p. 14090 - 14094
(2020/10/19)
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- Ligand-Receptor Interactions via Hydrogen-Bond Formation. Synthesis and Pharmacological Evaluation of Pyrrolo and Pyrido Analogues of the Cardiotonic Agent 7-Hydroxycyclindole
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The syntheses of N,N-dimethyl-6,7,8,9-tetrahydro-3H,10H-pyrrolocarbazol-7-amine (8), N,N-dimethyl-7,8,9,10-tetrahydro-11H-pyridocarbazol-8-amine (9a), and the N,N,11-trimethyl analogue (9b) are described.The in vitro inotropic activity of these compounds, as well as the known cardiotonics amrinone and 7-hydroxycyclindole (7), was investigated.Compound 8, a pyrrolo analogue of 7, was devoid of inotropic activity, while the pyrido analogues 9 were equiactive to 7 and amrinone.These results suggest that the hydroxyl group of 7 functions as an H-bondacceptor, rather than a donor, and that on interaction of 7, and the pyrido analogues 9, with a common receptor, an orbital occupied by one of the oxygen lone pair electrons of 7 must assume the same orientation as the orbital occupied by the pyridine nitrogen lone pair.
- Dionne, Gervais,Humber, Leslie G.,Asselin, Andre,McQuillan, Juanita,Treasurywala, Adi M.
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p. 1452 - 1457
(2007/10/02)
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- 4-[-(Alkoxy or polyhaloalkoxy)-benzamido]cyclohexanones
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3-R-3-(Ac2 NH)-9-R'-9-(Ac1 NH)-1,5-dioxaspiro[5.5]undecane (I), where R and R' are each hydrogen or lower-alkyl, Ac1 is lower-alkanoyl or 4-Q1 -benzoyl and Ac2 is 4-Q2 -benzoyl where Q1 and Q2 each is lower-alkoxy or polyhalo-lower-alkoxy, are antifertility agents. The compounds are prepared by di-acylating 3-R-9-R'-1,5-dioxaspiro[5.5]undecan-3,9-diamine (II) or mono-acylating 9-(Ac1 NH)-3-R-9-R'-1,5-dioxaspiro[5.5]undecan-3-amine (IV). IV and II are prepared by oxidizing 4-(Ac1 NH)-4-R'-cyclohexanol (VI) to produce 4-(Ac1 NH)-4-R'-cyclohexanone (VII), reacting VII with 2-NO2 -2-R-1,3-propanediol to produce 3-R-3-NO2 -9-(Ac1 NH)-9-R'-1,5-dioxaspiro[5.5]undecane (VIII), reducing VIII to produce the corresponding 3-amine (IV) and hydrolyzing IV to the corresponding 3,9-diamine (II). Methods of preparing VI are shown.
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