59-49-4Relevant academic research and scientific papers
A novel one-step photocatalytic synthesis of benzo[d]oxazol-2(3H)-one with C-doped TiO2 nanoparticle
Wang, Huqun,Zhang, Zhimin,Chang, Wenfu
, p. 1156 - 1157 (2008)
A novel approach was proposed to synthesize benzo[d]oxa-zol-2(3H)-one by photoreduction of o-nitrophenol and cyclization with urea using C-doped TiO 2 nanoparticles as photocatalyst which was prepared by a modified sol-gel method using glucose as carbon source. Copyright
Design, synthesis, and docking studies of new 2-benzoxazolinone derivatives as anti-HIV-1 agents
Safakish, Mahdieh,Hajimahdi, Zahra,Zabihollahi, Rezvan,Aghasadeghi, Mohammad R.,Vahabpour, Rouhoullah,Zarghi, Afshin
, p. 2718 - 2726 (2017)
A new class of 2-benzoxazolinone derivatives was designed and synthesized for its anti-human immunodeficiency virus-1 activity. The benzoxazolinone scaffold could be replaced with catechol moiety in the potent but toxic integrase strand transfer inhibitors. The biological evaluation of the synthesized compounds revealed that all compounds were active against human immunodeficiency virus-1 at 100 μM. It is also found that most of the compounds presented no significant cytotoxicity at concentration of 100 μM. The most potent compound with thiadiazole ring as the linker inhibited the human immunodeficiency virus-1 with 84% rate. Docking of this structure in the active site of prototype foamy virus integrase indicated that the chelation of two Mg2+ cations might be the probable mechanism of the anti-human immunodeficiency virus-1 activity. Our results indicated that the synthesized compounds can provide a very good basis for the development of new anti-human immunodeficiency virus-1 agents.
Aminolysis of cyclic carbamate analogs of carboxybiotin; metallic catalysis and modelling of carboxytransferase
Botella,Klaebe,Perie,Monnier
, p. 5111 - 5122 (1992)
Aminolysis of carbamic esters, a model of the intermediate carboxybiotin in enzymatic carboxylations was studied in organic medium in the presence of a divalent cation. This study establishes electrostatic catalysis of aminolysis, the rate determining step of which is the collapse of the tetrahedral intermediate principally by carbon-nitrogen bond breaking. The results also account for the role of the divalent cation present in the carboxytransferase subunit of carboxylases.
Chain Walking as a Strategy for Iridium-Catalyzed Migratory Amidation of Alkenyl Alcohols to Access α-Amino Ketones
Baek, Seung Beom,Chang, Sukbok,Hwang, Yeongyu,Kim, Dongwook
supporting information, p. 4277 - 4285 (2022/03/08)
Catalytic carbon-nitrogen bond formation in hydrocarbons is an appealing synthetic tool to access valuable nitrogen-containing compounds. Although a number of synthetic approaches have been developed to construct a bifunctional α-amino carbonyl scaffold in this realm, installation of an amino functionality at the remote and unfunctionalized aliphatic sites remains underdeveloped. Here we present a tandem iridium catalysis that enables the redox-relay amidation of alkenyl alcohols via chain walking and metal-nitrenoid transfer, which eventually offers a new route to various α-amino ketones with excellent regioselectivity. The virtue of this transformation is that an unrefined isomeric mixture of alkenyl alcohols can be utilized as the readily available starting materials to lead to the regioconvergent amidation. Mechanistic investigations revealed that the reaction proceeds via a tandem process involving two key components of redox-relay chain walking and intermolecular nitrenoid transfer with the assistance of hydrogen bonding, thus representing the competence of Ir catalysis for the olefin migratory C-N coupling with high efficiency and exquisite selectivity.
Synthesis and biological evaluation of some 1,3-benzoxazol-2(3H)-one hybrid molecules as potential antioxidant and urease inhibitors
Yilmaz, Fatih,Mente?e, Emre,S?kmen, Bahar Bilgin
, p. 260 - 269 (2020/10/21)
A new series of 1,3-benzoxazol-2(3H)-one hybrid compounds, including coumarin, isatin 1,3,4-triazole and 1,3,4-thiadiazole moieties, were synthesized and biologically evaluated for their antioxidant capacities and anti-urease properties. The synthesized benzoxazole-coumarin (6a–e) and benzoxazole-isatin (10a–c) hybrids showed remarkable urease inhibitory activities with IC50 (μM), ranging from 0.0306 ± 0.0030 to 0.0402 ± 0.0030, while IC50 of standard thiourea is 0.5027 ± 0.0293. The synthesized benzoxazole-triazole (8a–c) and benzoxazole-thiadiazole (9a–c) hybrids showed similar urease inhibitory activities with IC50 (μM), ranging from 0.3861 ± 0.0379 to 0.5126 ± 0.0345. The antioxidant activity of the synthesized compounds was evaluated for their antioxidant activities, such as reducing power and ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt) radical scavenging. The results of ABTS radical scavenging activities of some of the synthesized molecules showed higher activities than standard Trolox, SC50 (μM) = 213.04 ± 18.12. One benzoxazole-coumarin (6f), two benzoxazole-isothiocyanate (7b, 7c), and two benzoxazole-triazole (8b, 8c) derivatives showed higher activities (SC50 (μM) values, 82.07 ± 10.34, 120.19 ± 7.30, 104.58 ± 10.55, 153.26 ± 7.14, and 144.82 ± 10.68, respectively) than standard Trolox, (SC50 (μM) = 213.04 ± 18.12).
Enzyme-Inspired Lysine-Modified Carbon Quantum Dots Performing Carbonylation Using Urea and a Cascade Reaction for Synthesizing 2-Benzoxazolinone
Hasani, Morteza,Kalhor, Hamid R.
, p. 10778 - 10788 (2021/09/08)
Catalysts as the dynamo of chemical reactions along with solvents play paramount roles in organic transformations in long-lasting modes. Thus, developing effective and biobased catalysts in nontoxic solvents is highly in demand. In this report, carbon quantum dots (CQDs) functionalized with-lysine (Lys-CQDs) were generated from entirely nature-derived materials; they were demonstrated to be a promising catalyst for C-N bond formation in choline chloride urea (ChCl/U), a natural deep eutectic solvent (NADES). Among a number of synthesized CQDs, Lys-CQD turned out to be a powerful catalyst in the model reaction with aniline to afford phenyl urea. This type of transformation is important because aniline as a nucleophile has low activity, and urea is a very weak electrophile but an abundant natural source of the carbonyl moiety at the same time. The optimized reaction was performed under a highly desirable condition without using tedious and toxic workup processes at a low temperature (37 °C for aliphatic amines and 60 °C for aniline derivatives), as well as by embracing the broad scope of products in good to high yields even with weak nucleophiles such as aniline. A proposed acid-activated mechanism was suggested for the model reaction that was further confirmed by detecting ammonia as the leaving group. To show further multifunctionality of the catalyst, a cascade catalysis approach was developed for synthesizing 2-benzoxazolinone, which was furnished in a two-step transformation, starting from 2-aminophenol. Using X-ray crystallography, the structure of the final product in the cascade reaction was also determined. The catalyst was characterized using various analytical techniques including SEM, TEM, AFM, XRD, IR spectroscopy, UV-vis spectroscopy, DLS, and fluorescence spectroscopy. Measuring the acid/base sites by back titration, the catalyst was shown to be highly functionalized by the lysine functional group. The size of the catalyst was determined to be in the range of 1-8 nm, having a well-dispersed surface. In all, Lys-modified CQD, as a metal-free catalyst, was synthesized, characterized, and optimized for carbonylation, as well as a cascade reaction, under mild conditions. The whole process including catalyst synthesis and organic transformations is economically competitive and fulfills all requirements toward viability.
Synthesis and in silico studies of Novel Ru(II) complexes of Schiff base derivatives of 3-[(4-amino-5-thioxo-1,2,4-triazole-3-yl)methyl]-2(3H)-benzoxazolone compounds as potent Glutathione S-transferase and Cholinesterases Inhibitor
Adiguzel, Ragip,Türkan, Fikret,Yildiko, ümit,Aras, Abdülmelik,Evren, Enes,Onkol, Tijen
, (2021/02/03)
Novel Ru(II) complexes of Shiff base derivatives of 3-[(4-amino-5-thioxo-1,2,4-triazole-3-yl)methyl]-2(3H)-benzoxazolone were synthesized. The ligands (1a-e) were confirmed by IR, 1H NMR, and 13C NMR spectra (only 1b and 1c). Structures of the synthesized Ru(II) complexes (2a-e) were illuminated by elemental analysis, IR, 1H NMR, 13C NMR, and mass spectra. As the biological studies, the inhibitory potency of the ligands and the novel synthesized complexes were evaluated against the glutathione S-transferase (GST), acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes in vitro conditions. Ki values in the range of 26.87-47.63 μM for AChE, 23.51-42.81 μM for BChE, and 33.14-51.73 μM for GST, respectively. The free binding energy of most active inhibitors against AChE, BChE, and GST enzymes were detected as -10.183 kcal/mol, -9.111 kcal/mol, and -6.097 kcal/mol, respectively. All compounds docked were observed to bind in the active site of the enzymes with similar binding orientation and binding interactions with the surrounding amino acids.
Continuous-Flow Hofmann Rearrangement Using Trichloroisocyanuric Acid for the Preparation of 2-Benzoxazolinone
Baxendale, Ian R.,Gambacorta, Guido
, (2022/02/01)
A continuous-flow preparation of 2-benzoxazolinone via the Hofmann rearrangement of salicylamide has been implemented employing trichloroisocyanuric acid as the stable and atom-economic chlorinating agent. The system was optimized to avoid solid accumulation and allow the preparation of hundreds of grams of the pure desired material over a working day. Furthermore, a trichloroisocyanuric acid (TCCA)-based chlorination of 2-benzoxazolone to the corresponding 5-chloro derivative was also carried out under batch conditions.
Versatile Cp*Co(III)(LX) Catalyst System for Selective Intramolecular C-H Amidation Reactions
Chang, Sukbok,Jung, Hoimin,Kim, Dongwook,Lee, Jeonghyo,Lee, Jia,Park, Juhyeon
supporting information, p. 12324 - 12332 (2020/08/06)
Herein, we report the development of a tailored cobalt catalyst system of Cp*Co(III)(LX) toward intramolecular C-H nitrene insertion of azidoformates to afford cyclic carbamates. The cobalt complexes were easy to prepare and bench-stable, thus offering a convenient reaction protocol. The catalytic reactivity was significantly improved by the electronic tuning of the bidentate LX ligands, and the observed regioselectivity was rationalized by the conformational analysis and DFT calculations of the transition states. The superior performance of the newly developed cobalt catalyst system could be broadly applied to both C(sp2)-H and C(sp3)-H carbamation reactions under mild conditions.
Method for preparing carbonyl heterocyclic compound
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Paragraph 0036-0040; 0096-0101, (2020/03/25)
The invention provides a method for preparing a carbonyl heterocyclic compound, wherein Lewis base and hydrosilane are used as accelerators and can efficiently enable an ortho-substituted aniline compound to react with normal-pressure CO2 to generate corresponding carbonyl heterocyclic compounds containing different functional groups under mild conditions (100 DEG C, digital). According to the method, normal-pressure CO2 is used as an environmentally-friendly non-toxic carbonylation reagent, and cheap Lewis base and PMHS (industrial silicon waste) are used as accelerators, so that the use of CO, high-pressure CO2 and noble metal catalysts is avoided, the intermediate isocyanate does not need to be purified and separated, the pure product can be obtained only through simple suction filtration and separation after the reaction is finished, and the synthetic method is efficient and universal, is suitable for preparing a series of benzimidazolone, benzoxazolone and benzothiazolone compounds and has high industrial application value.
