2211-64-5Relevant academic research and scientific papers
Analogues of the Herbicide, N-Hydroxy- N-isopropyloxamate, Inhibit Mycobacterium tuberculosis Ketol-Acid Reductoisomerase and Their Prodrugs Are Promising Anti-TB Drug Leads
Kandale, Ajit,Patel, Khushboo,Hussein, Waleed M.,Wun, Shun Jie,Zheng, Shan,Tan, Lendl,West, Nicholas P.,Schenk, Gerhard,Guddat, Luke W.,McGeary, Ross P.
, p. 1670 - 1684 (2021/02/27)
New drugs to treat tuberculosis (TB) are urgently needed to combat the increase in resistance observed among the current first-line and second-line treatments. Here, we propose ketol-acid reductoisomerase (KARI) as a target for anti-TB drug discovery. Twenty-two analogues of IpOHA, an inhibitor of plant KARI, were evaluated as antimycobacterial agents. The strongest inhibitor of Mycobacterium tuberculosis (Mt) KARI has a Ki value of 19.7 nM, fivefold more potent than IpOHA (Ki = 97.7 nM). This and four other potent analogues are slow- and tight-binding inhibitors of MtKARI. Three compounds were cocrystallized with Staphylococcus aureus KARI and yielded crystals that diffracted to 1.6-2.0 ? resolution. Prodrugs of these compounds possess antimycobacterial activity against H37Rv, a virulent strain of human TB, with the most active compound having an MIC90 of 2.32 ± 0.04 μM. This compound demonstrates a very favorable selectivity window and represents a highly promising lead as an anti-TB agent.
Phyllosilicate-derived Nickel-cobalt Bimetallic Nanoparticles for the Catalytic Hydrogenation of Imines, Oximes and N-heteroarenes
Ciotonea, Carmen,Hammi, Nisrine,Dhainaut, Jérémy,Marinova, Maya,Ungureanu, Adrian,El Kadib, Abdelkrim,Michon, Christophe,Royer, Sébastien
, p. 4652 - 4663 (2020/08/19)
The development of cost-effective, noble metal-free catalytic systems for the hydrogenation of unsaturated aliphatic, aromatic, and heterocyclic compounds is fundamental for future valorization of general feedstock. With this aim, we report here the preparation of highly dispersed bimetallic Ni/Co nanoparticles (NPs), by a one-pot deposition-precipitation of Ni and Co phases onto mesoporous SBA-15 silica. By adjusting the chemical composition in the starting mixture, three supported catalysts with different Ni to Co weight ratios were obtained, which were further subjected to treatments under reducing conditions at high temperatures. Characterization of the resulting solids evidenced a homogenous distribution of Ni and Co elements forming the NPs, the best results being obtained for Ni/Co-2 : 2 samples, for which 50 wt.percent Ni–50 wt.percent Co NPs are found located on the surface of the residual phyllosilicate. Ni/Co-2 : 2, presenting the best performances for the hydrogenation of 2-methyl-quinoline, was further evaluated in the catalytic hydrogenation of selected imines, oximes and N-heteroarenes. Due to the high dispersion of bimetallic Ni?Co NPs, excellent properties (activity and selectivity) in the conversion of the selected substrates are reported.
Direct N-O bond formation via oxidation of amines with benzoyl peroxide
Banerjee, Amit,Yamamoto, Hisashi
, p. 2124 - 2129 (2019/02/20)
Herein, we report a general and efficient method for direct N-O bond formation without undesirable C-N bond (amide) formation starting from commercially available amines and benzoyl peroxide. The oxidation of 1,2-diamines to furnish bis-(benzoyloxy)-1,2-diamines is reported for the first time. We found that a significant amount of water (BPO?:?water = 3?:?1) in combination with Cs2CO3 is necessary to achieve high selectivity and yield. The reaction conditions are applicable to a wide range of 1,2-diamine and 1,2-disubstituted-1,2-diamine substrates. Additionally this method is highly applicable to primary and secondary amines. Further, the present method can access chiral bis-hydroxamic acids and bis-hydroxyl amines in just two steps from 1,2-diamines. The reaction conditions are simple, mild and inert atmosphere free. The synthetic potential of this methodology is further demonstrated in the short synthesis of a chiral BHA ligand.
Synthesis, Characterization, and Catalytic Activities of Palladium Complexes with Phenylene-Bridged Bis(thione) Ligands
Jia, Wei-Guo,Gao, Li-Li,Wang, Zhi-Bao,Sun, Li-Ying,Han, Ying-Feng
, p. 1946 - 1954 (2019/05/08)
The neutral phenylene-bridged bis(thione) compounds, 1,3-bis(3′-ethylimidazolyl-2′-thione)benzene (Betb), 1,3-bis(3′-butylimidazolyl-2′-thione)benzene (Bbtb), and 1,3-bis(3′-allylimidazolyl-2′-thione)benzene (Batb), have been synthesized and characterized. Reactions of palladium precursor PdCl2(CH3CN)2 with phenylene-bridged bis(thione) ligands in 1:2 ratio resulted in the formation of the complexes: PdCl2(L)2 (L = Betb, 3a; L = Bbtb, 3b; L = Batb, 3c, respectively). In contrast, treatment of the ligands with PdCl2(CH3CN)2 in 1:1 ratio gave cyclometalation palladium complexes Pd2+Cl(L-) (L = Betb-H, 4a; L = Bbtb-H, 4b; L = Batb-H, 4c) through the metal-induced C-H activation. Complexes 4a-c can also be obtained by the reaction of bis(thione) ligands and PdCl2 in 1:1 ratio. The reaction of 3a-c with additional PdCl2(CH3CN)2 also afforded complexes 4a-c. All ligands and palladium complexes were fully characterized by one-/two-dimensional NMR spectra, mass spectrometry, and infrared spectrometry. And the molecular structures of 3a-c, 4a, and 4c have been determined by the single-crystal X-ray diffraction method. Furthermore, the detailed spectroscopic properties and catalytic activities of the complexes for the reduction of nitro compounds were discussed in terms of the modification of the coordination ligands to the center metal.
Direct and Selective 3-Amidation of Indoles Using Electrophilic N-[(Benzenesulfonyl)oxy]amides
Ortiz, Gerardo X.,Hemric, Brett N.,Wang, Qiu
supporting information, p. 1314 - 1317 (2017/03/23)
Selective C-H amidation of 1H-indoles at the C3 position is reported as a direct entry to biologically important 3-aminoindoles. This transformation is achieved using novel N-[(benzenesulfonyl)oxy]amides as electrophilic nitrogen agents in the presence of ZnCl2. Interestingly, analogous reactions in the absence of ZnCl2 resulted in the formation of indole aminal products.
An efficient synthesis of: N -nitrosamines under solvent, metal and acid free conditions using tert -butyl nitrite
Chaudhary, Priyanka,Gupta, Surabhi,Muniyappan, Nalluchamy,Sabiah, Shahulhameed,Kandasamy, Jeyakumar
, p. 2323 - 2330 (2016/05/19)
Synthesis of various N-nitroso compounds from secondary amines is reported using tert-butyl nitrite (TBN) under solvent free conditions. Broad substrate scope, metal and acid free conditions, easy isolation procedure and excellent yields are few important features of this methodology. The acid labile protecting groups such as tert-butyldimethylsilyl (TBDMS) and tert-butyloxycarbonyl (Boc) as well as sensitive functional groups such as phenols, olefins and alkynes are found to be stable under the standard reaction conditions. Besides N-nitrosation, TBN is also found to be an efficient reagent in few other transformations including aryl hydrazines to aryl azides and primary amides to carboxylic acids under mild conditions.
One-pot synthesis of dihydrobenzisoxazoles from hydroxylamines, acetylenedicarboxylates, and arynes via in situ generation of nitrones
Li, Pan,Wu, Chunrui,Zhao, Jingjing,Li, Yang,Xue, Weichao,Shi, Feng
, p. 43 - 50 (2013/03/14)
Aryne [3 + 2] cycloaddition with nitrones generated in situ from the addition of hydroxylamines to acetylenedicarboxylates affords moderate to good yields of dihydrobenzisoxazoles. This reaction extends the current scope of aryne cycloaddition to include in situ generated nitrones and produces functionalized dihydrobenzisoxazoles with a quaternary center.
Hydrogenation of nitrocyclohexane to cyclohexanone oxime over Pd/CNT catalyst under mild conditions
Liao, Hong-Guang,Xiao, Yan-Juan,Zhang, Hai-Ke,Liu, Ping-Le,You, Kui-Yi,Wei, Chao,Luo, He'An
experimental part, p. 80 - 84 (2012/04/10)
The Pd/C, Pt/C, Ni/CNT and Pd/CNT catalysts were prepared by impregnation method and characterized by BET, XRD, TEM and H2 chemisorption. These catalysts were tested in the hydrogenation of nitrocyclohexane to cyclohexanone oxime. The results show that 5% Pd/CNT catalyst exhibits good performance, it gives nitrocyclohexane conversion of 97.6% and cyclohexanone oxime selectivity of 85.9% under mild conditions of 0.2 MPa and 323 K. The products include cyclohexanone oxime, cyclohexylamine, cyclohexanol and N- cyclohexylhydroxylamine. It has been found that higher temperature is in favor of the formation of cyclohexylamine, while the amount of cyclohexanol decreases with the increment of reaction temperature.
Palladium-catalyzed silane/siloxane reductions in the one-pot conversion of nitro compounds into their amines, hydroxylamines, amides, sulfonamides, and carbamates
Rahaim Jr., Ronald J.,Maleczka Jr., Robert E.
, p. 3316 - 3340 (2008/09/17)
A combination of palladium(II) acetate, aqueous potassium fluoride, and polymethylhydrosiloxane (PMHS) facilitates the room-temperature reduction of aromatic nitro compounds to anilines. These reactions tend to be quick (30 min), high-yielding, and tolerate a range of other functional groups. Replacement of PMHS/KF with triethylsilane allows for the reduction of aliphatic nitro compounds to their corresponding hydroxylamines. Depending on the substrate, both conditions can allow for the in situ conversion of the product amines into amides, sulfonamides, and carbamates. Georg Thieme Verlag Stuttgart.
Phase-transfer catalysis for the synthesis of hydroxylamines from oximes using benzyltriethylammonium borohydride in methanol and under solid-phase conditions
Gopalakrishnan, Mannathusamy,Anandabaskaran, Thirunavukkarasu,Sureshkumar, Purusothaman,Thanusu, Jayaraman,Kumaran, Arumugam K.,Kanagarajan, Vijayakumar
, p. 50 - 51 (2007/10/03)
Effective phase-transfer catalysis methodologies for the reduction of oximes to hydroxylamines by a selective and versatile reducing agent, benzyltriethylammonium borohydride (BTEABH), in methanol and under solid-phase conditions are presented.
