- Electrooxidative Dearomatization to Spiroisoxazolines: Application to Total Synthesis of Xanthoisoxazoline B
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The synthesis of spiroisoxazoline molecules has been developed via anodic oxidative dearomatization of 4-methoxybenzyl oximes. The reaction is thought to proceed through 5-exo C?O bond-forming cyclization of oxime radicals with arenes on the basis of cycl
- Chen, Dengfeng,He, Tianyu,Jin, Yongcan,Huang, Shenlin
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supporting information
p. 286 - 290
(2021/11/13)
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- Metal-Free Deoxygenation of Chiral Nitroalkanes: An Easy Entry to α-Substituted Enantiomerically Enriched Nitriles
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A metal-free, mild and chemodivergent transformation involving nitroalkanes has been developed. Under optimized reaction conditions, in the presence of trichlorosilane and a tertiary amine, aliphatic nitroalkanes were selectively converted into amines or nitriles. Furthermore, when chiral β-substituted nitro compounds were reacted, the stereochemical integrity of the stereocenter was maintained and α-functionalized nitriles were obtained with no loss of enantiomeric excess. The methodology was successfully applied to the synthesis of chiral β-cyano esters, α-aryl alkylnitriles, and TBS-protected cyanohydrins, including direct precursors of four active pharmaceutical ingredients (ibuprofen, tembamide, aegeline and denopamine).
- Pirola, Margherita,Faverio, Chiara,Orlandi, Manuel,Benaglia, Maurizio
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supporting information
p. 10247 - 10250
(2021/06/18)
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- Oxygen surface groups of activated carbon steer the chemoselective hydrogenation of substituted nitroarenes over nickel nanoparticles
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Oxygen surface groups of activated carbon, produced by nitric acid treatment, are not only able to prevent Ni particles from sintering but are also able to preferentially interact with the nitro group of substituted nitroarenes. The resulting Ni/ACOX catalyst is highly active and chemoselective for hydrogenation of nitroarenes to produce functionalized anilines and oximes.
- Ren, Yujing,Wei, Haisheng,Yin, Guangzhao,Zhang, Leilei,Wang, Aiqin,Zhang, Tao
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supporting information
p. 1969 - 1972
(2017/02/15)
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- Controllable Synthesis of Mesoporous Iron Oxide Nanoparticle Assemblies for Chemoselective Catalytic Reduction of Nitroarenes
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Iron(III) oxide is a low-cost material with applications ranging from electronics to magnetism, and catalysis. Recent efforts have targeted new nanostructured forms of Fe2O3 with high surface area-to-volume ratio and large pore volume. Herein, the synthesis of 3D mesoporous networks consisting of 4-5 nm γ-Fe2O3 nanoparticles by a polymer-assisted aggregating self-assembly method is reported. Iron oxide assemblies obtained from the hybrid networks after heat treatment have an open-pore structure with high surface area (up to 167 m2 g-1) and uniform pores (ca. 6.3 nm). The constituent iron oxide nanocrystals can undergo controllable phase transition from γ-Fe2O3 to α-Fe2O3 and to Fe3O4 under different annealing conditions while maintaining the 3D structure and open porosity. These new ensemble structures exhibit high catalytic activity and stability for the selective reduction of aryl and alkyl nitro compounds to the corresponding aryl amines and oximes, even in large-scale synthesis.
- Papadas, Ioannis T.,Fountoulaki, Stella,Lykakis, Ioannis N.,Armatas, Gerasimos S.
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p. 4600 - 4607
(2016/03/22)
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- Synthesis of Nitriles from Aldoximes and Primary Amides Using XtalFluor-E
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The dehydration reaction of aldoximes and amides for the synthesis of nitriles using [Et2NSF2]BF4 (XtalFluor-E) is described. Overall, the reaction proceeds rapidly (normally 1 h) at room temperature in an environmentally benign solvent (EtOAc) with only a slight excess of the dehydrating agent (1.1 equiv). A broad scope of nitriles can be prepared, including chiral nonracemic ones. In addition, in a number of cases, further purification of the nitrile after the workup was not required.
- Keita, Massaba,Vandamme, Mathilde,Paquin, Jean-Fran?ois
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p. 3758 - 3766
(2015/11/28)
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- Synthesis and biochemical evaluation of δ2-isoxazoline derivatives as DNA methyltransferase 1 inhibitors
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A series of Δ2-isoxazoline constrained analogues of procaine/procainamide (7a-k and 8a-k) were prepared and their inhibitory activity against DNA methyltransferase 1 (DNMT1) was tested. Among them, derivative 7b is far more potent in vitro (IC50 = 150 μM) than other non-nucleoside inhibitors and also exhibits a strong and dose-dependent antiproliferative effect against HCT116 human colon carcinoma cells. The binding mode of 7b with the enzyme was also investigated by means of a simple competition assay as well as of docking simulations conducted using the recently published crystallographic structure of human DNMT1. On the basis of the findings, we assessed that the mode of inhibition of 7b is consistent with a competition with the cofactor and propose it as a novel lead compound for the development of non-nucleoside DNMT inhibitors.
- Castellano, Sabrina,Kuck, Dirk,Viviano, Monica,Yoo, Jakyung,López-Vallejo, Fabian,Conti, Paola,Tamborini, Lucia,Pinto, Andrea,Medina-Franco, José L.,Sbardella, Gianluca
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experimental part
p. 7663 - 7677
(2011/12/21)
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- Intermolecular cope-type hydroamination of alkenes and alkynes
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(Chemical Equation Presented) Keep it simple! Intermolecular hydroamination can be achieved simply upon heating alkynes and alkenes with aqueous hydroxylamine. Alkynes react to afford oximes in good to excellent yields, and the formation of Markovnikov products is favored. A mechanism involving Cope-type hydroamination followed by bimolecular proton transfer is suggested and supported by DFT studies.
- Beauchemin, Andre M.,Moran, Joseph,Lebrun, Marie-Eve,Seguin, Catherine,Dimitrijevic, Elena,Zhang, Lili,Gorelsky, Serge I.
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p. 1410 - 1413
(2008/12/23)
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- Intermolecular Cope-type hydroamination of alkenes and alkynes using hydroxylamines
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The development of the Cope-type hydroamination as a method for the metal- and acid-free intermolecular hydroamination of hydroxylamines with alkenes and alkynes is described. Aqueous hydroxylamine reacts efficiently with alkynes in a Markovnikov fashion to give oximes and with strained alkenes to give N-alkylhydroxylamines, while unstrained alkenes are more challenging. N-Alkylhydroxy-lamines also display similar reactivity with strained alkenes and give modest to good yields with vinylarenes. Electron-rich vinylarenes lead to branched products while electron-deficient vinylarenes give linear products. A beneficial additive effect is observed with sodium cyanoborohydride, the extent of which is dependent on the structure of the hydroxylamine. The reaction conditions are found to be compatible with common protecting groups, free OH and NH bonds, as well as bromoarenes. Both experimental and theoretical results suggest the proton transfer step of the N-oxide intermediate is of vital importance in the intermolecular reactions of alkenes. Details are disclosed concerning optimization, reaction scope, limitations, and theoretical analysis by DFT, which includes a detailed molecular orbital description for the concerted hydroamination process and an exhaustive set of calculated potential energy surfaces for the reactions of various alkenes, alkynes, and hydroxylamines.
- Moran, Joseph,Gorelsky, Serge I.,Dimitrijevic, Elena,Lebrun, Marie-Eve,Bedard, Anne-Catherine,Seguin, Catherine,Beauchemin, Andre M.
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supporting information; experimental part
p. 17893 - 17906
(2009/07/18)
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- Gold catalysts open a new general chemoselective route to synthesize oximes by hydrogenation of α,β-unsaturated nitrocompounds with H 2
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The unprecedented chemoselective reduction of α,β-unsaturated nitroalkenes to oximes using hydrogen has been achieved with gold nanoparticles supported on TiO2. In contrast to the excellent catalytic performance of gold, related palladium and platinum catalysts are unselective, leading to the reduction of C=C double bond as well as the reduction of the NO2 to NH2. The selectivity of Au/TiO2 for the formation of oximes opens the way for the general use of the Henry reaction in organic synthesis. Copyright
- Corma, Avelino,Serna, Pedro,Garcia, Hermenegildo
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p. 6358 - 6359
(2008/02/09)
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- The Oxidation of 3-Aryl-1-propenes by Oxidative System of RuCl 3-NaIO4-Phase Transfer Catalyst
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Methyleugenol 1a was oxidized to give 3,4-dimethoxyphenylacetaldehyde by the oxidative system containing the RuCl3-NaIO4-phase transfer catalyst. The yield and spectroscopic properties were obtained from the stable acetaldoxim 3a. Furthermore, this oxidation system could be applied to other arylpropenes, thus, safrole, 4-methoxyallylbenzene, allylbenzene, and the corresponding arylacetaldehyde formed.
- Yuasa, Yoshifumi,Shibuya, Shiroshi,Yuasa, Yoko
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p. 3947 - 3952
(2007/10/03)
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- REDUCTION OF α,β-UNSATURATED NITROCOMPOUNDS WITH TRIBUTYLTIN HYDRIDE
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Nitroalkenes upon treatment with tributyltin hydride in the absence of any catalyst provide a new method for the reduction of α,β-unsaturated nitrocompounds.Oxidative cleavage of the intermediate stannyl nitronates yielded carbonyl compounds in good yields.
- Aizpurua, J. M.,Oiarbide, M.,Palomo, C.
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p. 5365 - 5366
(2007/10/02)
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