- Pd-ZnO nanowire arrays as recyclable catalysts for 4-nitrophenol reduction and Suzuki coupling reactions
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In this work, we report a facile approach for the preparation of Pd nanoparticle-ZnO nanowire arrays followed by demonstrating their use as recyclable catalyst for reactions under different conditions. The facile synthesis largely relies on a spontaneous reduction of PdCl42? at the surface of oriented ZnO nanowires grown on a Zn foil. This is due to a combination of the strongly reducing ability of Zn foil and the semiconducting nature of ZnO nanowires. At room temperature and under a weak alkaline condition, the as-prepared Pd nanoparticle-ZnO nanowire arrays show a catalytic activity factor up to 76.6 s?1 g?1 in the reduction of 4-nitrophenol and no obvious decreases in the catalytic activity even after use of 10 times. Meanwhile, the as-prepared Pd nanoparticle-ZnO nanowire arrays exhibit extraordinary catalytic activity toward Suzuki and carbonylative Suzuki reactions at a higher temperature under a stronger alkaline condition. The outstanding performance of the hybrid nanowire arrays is mainly originated from the small size of the Pd nanoparticles (~2-4 nm) with clean surfaces, as well as a strong affinity between the Pd nanoparticles and ZnO nanowires, leading to marginable catalyst loss and aggregation. Considering the multiple choices of both noble metal nanocatalyst and transition metal oxide nanowire array, we expect noble metal nanoparticle-transition metal oxide nanowire arrays to be emerged as a new class of recyclable catalysts attractive for diverse organic reactions to develop pharmaceuticals, natural products and advanced functional materials.
- Hu, Qiyan,Liu, Xiaowang,Tang, Lin,Min, Dewen,Shi, Tianchao,Zhang, Wu
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p. 7964 - 7972
(2017/02/05)
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- Chemoselective Transformation of Diarylethanones to Arylmethanoic Acids and Diarylmethanones and Mechanistic Insights
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The chemoselective transformation of diarylethanones via either aerobic oxidative cleavage to give arylmethanoic acids or tandem aerobic oxidation/benzilic acid rearrangement/decarboxylation to give diarylmethanones has been developed. The transformation is controllable and applicable to a broad spectrum of substrates and affords the desired products in good to excellent yields. Mechanistic insights with control reactions, 1H NMR tracking, and single-crystal X-ray diffraction reveal a complex mechanistic network in which two common intermediates, α-ketohydroperoxide and diarylethanedione, and three plausible pathways are proposed and verified. These pathways are interlinked and can be switched reasonably by changing the reaction conditions. This method enables scalable synthesis and access to a number of valuable compounds, including vitamin B3, diphenic acid, and the nonsteroidal anti-inflammatory drug ketoprofen. The present protocol represents a step forward in exploiting complex mechanistic networks to control reaction pathways, achieving divergent syntheses from the same class of starting materials.
- Wang, Xing,Chen, Rui-Xi,Wei, Zeng-Feng,Zhang, Chen-Yang,Tu, Hai-Yang,Zhang, Ai-Dong
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p. 238 - 249
(2016/01/15)
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- METHYLENE LINKED QUINOLINYL MODULATORS OF ROR-GAMMA-T
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The present invention comprises compounds of Formula (I). wherein: R1, R2, R3, R4, R5, R6, R7, R8, and R9 are defined in the specification. The invention also comprises a method of treating or ameliorating a syndrome, disorder or disease, wherein said syndrome, disorder or disease is rheumatoid arthritis or psoriasis. The invention also comprises a method of modulating RORγt activity in a mammal by administration of a therapeutically effective amount of at least one compound of claim 1.
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Page/Page column 104; 106
(2015/05/05)
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- METHYLENE LINKED QUINOLINYL MODULATORS OF RORyt
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The present invention comprises compounds of Formula I. wherein: R1, R2, R3, R4, R5, R6, R7, R8, and R9 are defined in the specification. The invention also comprises a method of treating or ameliorating a syndrome, disorder or disease, wherein said syndrome, disorder or disease is rheumatoid arthritis or psoriasis. The invention also comprises a method of modulating RORγt activity in a mammal by administration of a therapeutically effective amount of at least one compound of claim 1.
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Paragraph 0483; 0484; 0507; 0508
(2014/05/07)
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- Efficient, recyclable and phosphine-free carbonylative Suzuki coupling reaction using immobilized palladium ion-containing ionic liquid: Synthesis of aryl ketones and heteroaryl ketones
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The carbonylative Suzuki coupling reaction of aryl and heteroaryl iodides was studied by using immobilized palladium ion-containing ionic liquid (ImmPd-IL). The protocol was optimized with respect to various reaction parameters, applied to a wide variety of substituted aryl/heteroaryl iodides and various aryl/heteroaryl boronic acids with different steric and electronic properties, and afforded the corresponding products in good to excellent yield. This is an efficient, heterogeneous catalyst which avoids the use of phosphine ligands, and its reusability was tested in up to four consecutive cycles. The recycled catalyst was characterized by using XPS analysis.
- Khedkar, Mayur V.,Sasaki, Takehiko,Bhanage, Bhalchandra M.
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p. 7791 - 7797
(2013/06/27)
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- Ligand-free Pd-catalyzed carbonylative cross-coupling reactions under atmospheric pressure of carbon monoxide: Synthesis of aryl ketones and heteroaromatic ketones
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The carbonylative Suzuki cross-coupling reactions of boronic acids with aryl iodides catalyzed by Pd2(dba)3 as a ligand-free catalyst under atmospheric pressure of carbon monoxide has been firstly developed. Under mild reaction conditions, a broad range of aryl/heteroaryl iodides and aryl/heteroaryl boronic acids were selectively coupled to afford the corresponding diaryl ketones in good to excellent yields at low catalyst loadings (0.05 to 2 mol-%). Moreover, the catalyst can also be recycled. The carbonylative Suzuki cross-coupling reactions of boronic acids with aryl iodides catalyzed by Pd2(dba)3 as a ligand-free catalyst under an atmosphere of carbon monoxide has been developed. A broad range of aryl/heteroaryl iodides and aryl/heteroaryl boronic acids were selectively coupled to afford the corresponding diaryl ketones in good to excellent yields. The catalyst can also be recycled.
- Li, Hongling,Yang, Min,Qi, Yanxing,Xue, Jijun
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supporting information; experimental part
p. 2662 - 2667
(2011/06/25)
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- Pd/C: An efficient, heterogeneous and reusable catalyst for phosphane-free carbonylative suzuki coupling reactions of aryl and heteroaryl iodides
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The carbonylative Suzuki coupling reaction of aryl boronic acid with different aryl and heteroaryl iodides was carried out to synthesize various unsymmetrical biaryl ketones by using Pd/C as an efficient, heterogeneous and reusable catalyst. The catalyst exhibits remarkable activity, and its reusability was tested up to four consecutive cycles. The reaction is applicable for various aryl and heteroaryl iodides having different steric and electronic properties. It provides good to excellent yield of the desired products. The developed protocol is advantageous with regard to the ease in handling the catalyst and the simple work-up procedure; it is also an environmentally benign process with effective catalyst recyclability. A facile protocol has been developed for the carbonylative Suzuki coupling reaction of aryl and heteroaryl iodides with Pd/C as effective, heterogeneous, reusable catalyst. The system is applicable for a wide variety of aryl and heteroaryl iodides. Copyright
- Khedkar, Mayur V.,Tambade, Pawan J.,Qureshi, Ziyauddin S.,Bhanage, Bhalchandra M.
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experimental part
p. 6981 - 6986
(2011/03/17)
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- Phosphane-free palladium-catalyzed carbonylative suzuki coupling reaction of aryl and heteroaryl iodides
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The carbonylative cross-coupling reaction of an arylboronic acid with an aryl iodide and a heteroaryl iodide to give unsymmetrical biaryl ketones was carried out by using Pd(tmhd)2/Pd (OAc)2 as a phosphane-free catalyst. Various aryl and heteroaryl iodides with different arylboronic acid derivatives provided, good, to excellent yields of the desired products under optimized reaction conditions. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009.
- Tambade, Pawan J.,Patil, Yogesh P.,Panda, Anil G.,Bhanage, Bhalchandra M.
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experimental part
p. 3022 - 3025
(2009/11/30)
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- A Novel Approach to Dual-Acting Thromboxane Receptor Antagonist/Synthase Inhibitors Based on the Link of 1,3-Dioxane-Thromboxane Receptor Antagonists and -Thromboxane Synthase Inhibitors
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A new class of dual-acting racemic thromboxane receptor antagonist/thromboxane synthase inhibitors is reported, based on the novel approach of linking the known thromboxane synthase inhibitors (TXSI) dazoxiben (2) or isbogrel (11) (separately) to thromboxane receptor antagonists (TXRA) from the 1,3-dioxane series, such as ICI 192605 (10).Dual activity was observed in vitro with inhibition of human microsomal thromboxane synthase in the range IC50 = 0.01-1.0 μM and receptor antagonist activity by inhibition of U46619-induced human platelet aggregation in the range pA2 = 5.5-7.0.The in vitro results also showed that very large groups could be tolerated at the selected substitution positions of the TXRA and TXSI components.Oral activity was observed in ex vivo tests in both rats and dogs at a dose of 10 mg/kg.Thus, (E)-7--4-(2-hydroxyphenyl)-1,3-dioxan-2-yl>benzyl>oxy>phenyl>-7-(3-pyridyl)hept-6-enoic acid (110) was both an antagonist (pA2 = 6.7) and a synthase inhibitor (IC50 = 0.02 μM)).On oral dosing (10 mg/kg) to rats and dogs, 110 showed significant TXRA activity 64 (rat, 3 h) and >59 +/- 11.3 (dog, 2 h) vs ex vivo U46619-induced platelet aggregation>.Inhibition of thromboxane synthase at the respective time points in these experiments was 81 +/- 4.4percent (rat) and 69 +/- 4.8percent (dog).
- Ackerley, Norman,Brewster, Andrew G.,Brown, George R.,Clarke, David S.,Foubister, Alan J.,et al.
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p. 1608 - 1628
(2007/10/02)
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- Substituted anilide compounds which are useful in the treatment of arrhythmia
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A substituted anilide derivative of the formula STR1 wherein R1 represents a mononuclear or binuclear heterocyclic group which contains 1 to 3 nitrogen atoms as ring members and may have a substituent. A represents a single bond, a carbonyl gro
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- A New Simple Synthesis of Fusaric Acid and Other 5-Alkyl-2-pyridinecarboxylic Acids
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Carboxamido groups are introduced into the 6-position of 3-acylpyridines with high regioselectivity via Minisci reaction with formamides, Fe(II) sulfate and tert-butyl hydroperoxide.The isolation procedure is considerably improved by the addition of citric acid for complexation of the Fe ions.Fusaric acid and other 5-alkyl-2-pyridine carboxylic acids are obtained by a following Wolff-Kishner reaction in 20-75percent overall yield.
- Langhals, Elke,Langhals, Heinz,Ruechardt, Christoph
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p. 930 - 949
(2007/10/02)
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- Synthesis of 3-Aryl-3-pyridylallylamines Related to Zimelidine via Palladium-Catalyzed Amination
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Reaction of aryl pyridyl ketones 1 with vinylmagnesium bromide followed by acetylation of the products 2 with acetic anhydride/Et3N and with 4-(dimethylamino)pyridine (DMAP) as a catalyst gave acetates 3 in high yields.Treatment of acetates 3 with dimethylamine in the presence of a palladium catalyst produced a mixture of E and Z isomers of 3-aryl-3-pyridylallylamines 4.
- Baeckvall, Jan-E.,Nordberg, Ruth E.,Nystroem, Jan-E.,Hoegberg, Thomas,Ulff, Bengt
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p. 3479 - 3483
(2007/10/02)
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