- Catalyst for the degradation of 1,1-dimethylhydrazine and its by-product N-nitrosodimethylamine in propellant wastewater
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A three-component metal catalyst was prepared and used in the process of catalytic wet peroxide oxidation (CWPO) for the degradation of unsymmetrical dimethylhydrazine (UDMH) in propellant wastewater with H2O2. It was structurally characterized using scanning electron spectroscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDX), and its catalytic activity was evaluated using indexes such as the efficiency of UDMH degradation and chemical oxygen demand (COD) removal and the concentrations of ammonia (NH3-N), formaldehyde (HCHO), total nitrogen (TN), total organic carbon (TOC) and N-nitrosodimethylamine (NDMA). Besides, the reaction system was monitored using UV-Vis full wavelength scanning spectroscopy and liquid chromatography-mass spectroscopy (LC-MS). As a result, it was observed that the degradation mechanism involved OH attacking the amino group and homocoupling in UDMH with the simultaneous transformation of the active component CuII/I. Based on investigation of the reaction factors (H2O2 dosage, temperature, catalyst dosage, pH and initial concentration of UDMH) focusing on the removal of NDMA, the optimal conditions for CWPO with a three-component metal catalyst were determined. The high treatable concentration of UDMH (500 mg L-1), rapid rate and good reusability with a high efficiency of UDMH degradation and COD removal (99.9% in 10 min and 94.6% in 30 min, respectively) and the low concentration of NDMA are merits of the present catalyst.
- Liang, Meiling,Li, Weijie,Qi, Qi,Zeng, Pingchuan,Zhou, Yucheng,Zheng, Yingping,Wu, Min,Ni, Henmei
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- Synthesis and molecular properties of formic hydrazides
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The existence of 1,3-silatropic transformation in N',N'-dimethyl-N-(trimethylsilyl)formic hydrazide was discovered. In the crystal, its molecules form chains due to bifurcated hydrogen bonds.
- Belova, Liya O.,Pletneva, Maria V.,Golub, Nataliya A.,Kirilin, Aleksei D.,Sheludyakov, Viktor D.,Storozhenko, Pavel A.,Korlyukov, Alexander A.
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- N-Ammonium Ylide Mediators for Electrochemical C-H Oxidation
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The site-specific oxidation of strong C(sp3)-H bonds is of uncontested utility in organic synthesis. From simplifying access to metabolites and late-stage diversification of lead compounds to truncating retrosynthetic plans, there is a growing need for new reagents and methods for achieving such a transformation in both academic and industrial circles. One main drawback of current chemical reagents is the lack of diversity with regard to structure and reactivity that prevents a combinatorial approach for rapid screening to be employed. In that regard, directed evolution still holds the greatest promise for achieving complex C-H oxidations in a variety of complex settings. Herein we present a rationally designed platform that provides a step toward this challenge using N-ammonium ylides as electrochemically driven oxidants for site-specific, chemoselective C(sp3)-H oxidation. By taking a first-principles approach guided by computation, these new mediators were identified and rapidly expanded into a library using ubiquitous building blocks and trivial synthesis techniques. The ylide-based approach to C-H oxidation exhibits tunable selectivity that is often exclusive to this class of oxidants and can be applied to real-world problems in the agricultural and pharmaceutical sectors.
- Saito, Masato,Kawamata, Yu,Meanwell, Michael,Navratil, Rafael,Chiodi, Debora,Carlson, Ethan,Hu, Pengfei,Chen, Longrui,Udyavara, Sagar,Kingston, Cian,Tanwar, Mayank,Tyagi, Sameer,McKillican, Bruce P.,Gichinga, Moses G.,Schmidt, Michael A.,Eastgate, Martin D.,Lamberto, Massimiliano,He, Chi,Tang, Tianhua,Malapit, Christian A.,Sigman, Matthew S.,Minteer, Shelley D.,Neurock, Matthew,Baran, Phil S.
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supporting information
p. 7859 - 7867
(2021/05/26)
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- N-Isocyanodialkylamines generated in situ for the Joullié–Ugi reaction with indolenines
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N-Isocyanodialkylamines are rare isocyanide surrogates for the Ugi-type reactions. To avoid problems with instability and the obnoxious smell of these reagents, we optimized and employed a convenient protocol for in situ dehydration of N,N-dialkyl-N′-formyl hydrazines to give the respective N-isocyanodialkylamines which were utilized in the reaction with indolenines and acetic acid. The reaction was demonstrated to give modest to excellent yields of products incorporating the N-isocyanodialkylamine but not the carboxylic acid component.
- Golubev, Pavel,Krasavin, Mikhail
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supporting information
p. 3532 - 3536
(2018/08/29)
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- Sulfonic acid supported on hydroxyapatite-encapsulated-γ-Fe2O3 nanocrystallites as a magnetically Br?nsted acid for N-formylation of amines
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Treatment of aqueous formic acid (85%) with structurally diverse amines in the presence of a catalytic amount of sulfonic acid supported on hydroxyapatite-encapsulated-γ-Fe2O3 [HAp@-γ-Fe2O3] (0.9 mol.%) as a heterogeneous, reusable and highly efficient catalyst gave the corresponding formamides in good to excellent yields at room temperature. The magnetically catalytic system was recovered by-passing time consuming filtration operation by using an external magnet device. In addition to facility, this methodology, it also enhances product purity and promises economic as well as environmental benefits.
- Ma'mani, Leila,Sheykhan, Mehdi,Heydari, Akbar,Faraji, Mohammad,Yamini, Yadollah
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experimental part
p. 64 - 69
(2010/07/05)
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- An improved process for the preparation of trimethylhydrazine and its coupling with an activated acid intermediate
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Trimethylhydrazine (TMH) was prepared in two steps from 1,1-dimethylhydrazine, using an easy to scale-up procedure that avoided difficult acid-base extractions. The procedure provided TMH as a solution in 1,4-dioxane, in a form that was easy and safe to handle in a coupling with an enantiomerically pure, sterically hindered, Boc-protected-amino acid, 1. This key coupling reaction in the preparation of 3 was accomplished through the corresponding acid chloride, thereby avoiding the use of expensive coupling reagents.
- Garcia-Rubio, Silvina,Wilson, Chandra D.,Renner, Deborah A.,Rosser, John O.,Patra, Debasis,Gregory Reid,Pines, Seemon H.
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p. 360 - 362
(2013/09/05)
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- Compound with growth hormone releasing properties
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The present invention describes a new compound, 2-Amino-N-[(1R)-2-[(3R)-3-benzyl-3-(N,N′,N′-trimethylhydrazinocarbonyl)piperidin-1-y]-1-(1H-indol-3-ylmethyl)-2-oxoethyl]-2-methylpropionamide, having the formula: and pharmaceutically acceptable salts thereof, compositions containing them, and their use for treating medical disorders resulting from a deficiency in growth hormone.
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