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عنوان فارسی مقاله:
هیدروژن زدایی هوازی کتون حلقوی به فنول متناظر کاتالیست با نانوکاتالیستهای پالادیم ناهمگن
عنوان انگلیسی مقاله:
Aerobic dehydrogenation of cyclic ketones into corresponding phenols catalyzed by heterogeneous Pd nanocatalysts
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
The transformation of cyclohexanones into corresponding phenols is a fundamental reaction in organic chemistry. Phenols and its derivatives are commonly used in pharmaceuticals, bulk chemicals and polymers [1]. The preparation of phenols from ketones has been investigated previously [2–10]. Condensation of acyclic ketones with β-ketoaldehydes or β-diketones enable direct access to phenols but low product yields, limited access to starting materials, and formation of isomeric products have restricted the utility of these procedures [2]. The dehydrogenation of cyclic ketones affords cyclic enones or aromatic alcohol via removal of 1 or 2 equivalent of H2, respectively. Methods for formation of phenols via dehydrogenation of cyclohexenones typically use undesirable stoichiometric reagents, such as DDQ (2,3-dichloro-5,6-dicyano-1,4- benzoquinone); use stepwise procedures, such as bromination/ dehydrobromination; or require harsh reaction conditions (≥200 °C) that limit functional group compatibility [2–8,11]. Recently, the group of Stahl presented a Pd-based homogeneous system using O2 as the terminal oxidant for the aromatization of substituted cyclohexanones. Later a thorough investigation of the Pd (TFA)2/2-Me2Npy-catalyzed dehydrogenation of cyclohexanones and cyclohexenones, showing that an initial, highly active molecular Pd (II) species generate soluble Pd nanoparticles that serve as the active catalyst during steady-state dehydrogenation of the substrate [12–14]. In contrast, no effective heterogeneous catalytic method for dehydrogenation of substituted and unsubstituted cyclohexanones exist. Its great opportunity to create nanoparticle-based heterogeneous catalytic system for this important transformation. The heterogeneous catalyst can be easily separated from the reaction mixture by simple filtration and recycled several times. Here, we report a different Pd, Ni, Ni-Sn, Cu and Ag-Pd heterogeneous nano-catalyst systems, for direct dehydrogenation of cyclohexanones (1a) and 3-methyl-cyclohexanone (2a) to the corresponding phenols, in the presence of O2 as the oxidant.
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کلمات کلیدی:
Aerobic Dehydrogenation of Cyclohexanone to Phenol Catalyzed by ... pubs.acs.org/doi/abs/10.1021/ja403165u by D Pun - 2013 - Cited by 65 - Related articles May 13, 2013 - Palladium-Catalyzed Aerobic Dehydrogenation of Cyclic Hydrocarbons for the ... Conversion of Simple Cyclohexanones into Catechols. [PDF]Table 1 ir.xtbg.org.cn/.../Aerobic%20dehydrogenation%20of%20cyclic%20ketones%20into%... by M Shah - 2017 - Related articles Oct 26, 2016 - Aerobic dehydrogenation of cyclic ketones into corresponding phenols catalyzed by heterogeneous Pd nanocatalysts. Mazloom Shah a,b,c,⁎, ... Palladium-Catalyzed Aerobic Dehydrogenation of Substituted ... https://www.ncbi.nlm.nih.gov › NCBI › Literature › PubMed Central (PMC) by Y Izawa - 2011 - Cited by 206 - Related articles Jun 9, 2011 - ... for the introduction of a hydroxyl group into an aromatic ring, guided by ... The preparation of phenols from ketone precursors have been explored previously (8-16). ... of the reaction; the corresponding ortho-, meta-, and para-cresols were ... Palladium-catalyzed aerobic dehydrogenation of cyclic ketones. Palladium-Catalyzed Aerobic Dehydrogenation of Substituted ... - jstor https://www.jstor.org/stable/27978201 Jun 9, 2011 - cyclohexanones to the corresponding phenols. The reaction proceeds via ... into an aromatic ring, guided by steric rather than electronic ..... Palladium-catalyzed aerobic dehydrogenation of cyclic ketones. Reaction conditions ... Palladium-Catalyzed Aerobic Dehydrogenation of ... - Science science.sciencemag.org/content/sci/333/6039/209.full.pdf?explicitversion=true Feb 23, 2011 - cyclohexanones to the corresponding phenols. The reaction proceeds via ... into an aromatic ring, guided by steric rather than electronic .... Palladium-catalyzed aerobic dehydrogenation of cyclic ketones. Reaction conditions ... Aerobic oxidation of cyclohexanones to phenols and aryl ethers over ... pubs.rsc.org/en/Content/ArticleHtml/2015/QO/c4qo00354c Feb 12, 2015 - Dehydrogenation of ketones to synthesize enones is one of the important ... Li and Wang reported a direct aerobic dehydrogenation of aldehydes to the corresponding ... In general, cyclic enones and phenols were formed by .... transformation of cyclohexanones into cyclohexenones and phenols (Table 1).
