627-39-4Relevant articles and documents
Site-specific catalytic activities to facilitate solvent-free aerobic oxidation of cyclohexylamine to cyclohexanone oxime over highly efficient Nb-modified SBA-15 catalysts
Ding, Wei,Mao, Liqiu,Peng, Haoyu,Yin, Dulin,Zhong, Wenzhou
, p. 3409 - 3422 (2020/06/09)
The development of highly active and selective heterogeneous catalysts for efficient oxidation of cyclohexylamine to cyclohexanone oxime is a challenge associated with the highly sensitive nitrogen center of cyclohexylamine. In this work, dispersed Nb oxide supported on SBA-15 catalysts are disclosed to efficiently catalyze the selective oxidation of cyclohexylamine with high conversion (>75%) and selectivity (>84%) to cyclohexanone oxime by O2without any addition of solvent (TOF = 469.8 h?1, based on the molar amount of Nb sites). The role of the active-site structure identity in dictating the site-specific catalytic activities is probed with the help of different reaction and control conditions and multiple spectroscopy methods. Complementary to the experimental results, further poisoning tests (with KSCN or dehydroxylation reagents) and DFT computational studies clearly unveil that the surface exposed active centers toward activation of the reactants are quite different: the surface -OH groups can catch the NH2group from cyclohexylamine by forming a hydrogen bond and lead to a more facile cyclohexylamine oxidation to desired products, while the monomeric or oligomeric Nb sites with a highly distorted structure play a key role in the dissociation of O2molecules beneficial for insertion of active oxygen species into cyclohexylamine. These catalysts exhibit not only satisfactory recyclability for cyclohexylamine oxidation but also efficiently catalyze the aerobic oxidation of a wide range of amines under solvent-free conditions.
N-substituted alkyl arylxoy phenoxyl propanamide compound with herbicidal activity and preparation and application thereof
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Paragraph 0060; 0061; 0062; 0063, (2016/10/10)
The invention discloses an N-substituted alkyl arylxoy phenoxyl propanamide compound shown in the formula (I), a preparation method, a weeding composition and application of the composition for controlling malignant grassy weed in a rice field.
Iminoxyl radical-based strategy for intermolecular C=O bond formation: Cross-dehydrogenative coupling of 1,3-dicarbonyl compounds with oximes
Krylov, Igor B.,Terent'Ev, Alexander O.,Timofeev, Vladimir P.,Shelimov, Boris N.,Novikov, Roman A.,Merkulova, Valentina M.,Nikishin, Gennady I.
supporting information, p. 2266 - 2280 (2014/07/21)
Cross-dehydrogenative C=O coupling of 13-diketones and 1,3-keto esters with oximes was realized for the first time. The reaction proceeds in the presence of the oxidants [KMnO4, Mn(OAc)2/KMnO4, Mn(OAc)32 H2O, MnO2, Mn(acac)3, Fe(ClO4)3, Cu(ClO4)26 H 2O, Cu(NO3)22.5 H2O, and (NH 4)2Ce(NO3)6]. Twenty cross-coupling products were synthesized using potassium permanganate (KMnO4), manganese(II) acetate dihydrate [Mn(OAc)32 H2O], or the manganese(II) acetate/potassium permanganate [Mn(OAc)2/KMnO 4] system; yields are 27-92%. The synthesis can be easily scaled up to gram quantities of the target products. Apparently, the reaction proceeds via a radical mechanism in which the oxidizing agent serves to generate radicals from oximes and perform the one-electron oxidation of 1,3-dicarbonyl compounds. The formation of oxime radicals was confirmed quantitatively by electron spin resonance (ESR) spectroscopy. The coupling described in the present study is the first example of the selective intermolecular reaction involving unstable iminoxyl radicals generated in situ.
