614-20-0Relevant academic research and scientific papers
Fixation of carbon dioxide by oxalic amidinato magnesium complexes: Structures and reactions of trimetallic magnesium carbamato and related complexes
Ruben, Mario,Walther, Dirk,Knake, René,G?rls, Helmar,Beckert, Rainer
, p. 1055 - 1064 (2000)
The reaction of oxalic amidines R1-N=C(NHR2)-C(NHR2)=N-R1 with CH3MgX followed by uptake of CO2 results in the formation of the trimeric carbamato complexes [R1-N=C(NR2-COO)-C(NR2-COO)-C(NR2COO)=N- R1]3Mg3(THF)6 (2a: R1 = R2 = Ph; 2b: R1 = R2 = p-tolyl) as the thermodynamically stable final products of the reaction. Their X-ray crystal structures show that the three metal centres are in a linear arrangement. The central magnesium ion is octahedrally surrounded by six O-donor atoms of the μ2-carbamato bridges, while both peripheral magnesium ions are facially coordinated by three O-donor atoms of the carbamato groups and three THF molecules. This coordination sphere can be considered as a structural model for the active centre in the ribulose-1,5-bisphosphate carboxylase/oxygenase enzyme. Compound 2a reacts with ZnCl2 or CoBr2, with CO2 elimination, to form dimeric complexes of the type [X2M(oxalamidinato)MX2][Mg(DMF)6] (M = Zn, Co; X = Cl, Br). X-ray crystal structure analyses show that the d-metals are tetrahedrally coordinated. The magnesium-bromide-containing intermediates in the formation of 2a and 2b are able to transfer CO2 to acetophenone, thus simulating the CO2 activation step in enzymatic biotin-dependent carboxylation reactions.
Organocatalytic Asymmetric Decarboxylative Addition of β-Ketoacids to Methyleneindolinones Derivatives
Kumari, Anita,Kaur, Jasneet,Bhardwaj, Vimal K.,Chimni, Swapandeep Singh
, p. 4081 - 4088 (2018)
The quinine squaramide-catalyzed enantioselective decarboxylative addition reaction of various β-keto acids with methyleneindolinones has been developed. Through this methodology, various oxindole derivatives were synthesized in good yields (up to 93 %) and excellent enantiomeric excess (up to 99 % ee) and moderate diastereoselectivity (up to 66:34).
Enantioselective decarboxylative Mannich reaction of β-keto acids withC-alkynylN-BocN,O-acetals: access to chiral β-keto propargylamines
Chen, Li-Jun,Li, Wei,Shen, Bao-Chun,Sun, Zhong-Wen,Xie, Hui-Ding,Zhang, Cong-Cong
, p. 8607 - 8612 (2021/10/20)
The chiral keto-substituted propargylamines are an essential class of multifunctional compounds in the field of organic and pharmaceutical synthesis and have attracted considerable attention, but the related synthetic approaches remain limited. Therefore, a concise and efficient method for the enantioselective synthesis of β-keto propargylaminesviachiral phosphoric acid-catalyzed asymmetric Mannich reaction between β-keto acids andC-alkynylN-BocN,O-acetals as easily availableC-alkynyl imine precursors has been demonstrated here, affording a broad scope of β-ketoN-Boc-propargylamines in high yields (up to 97%) with generally high enantioselectivities (up to 97?:?3 er).
Synthetic method of lobeline hydrochloride
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Paragraph 0006; 0027; 0030; 0032; 0034, (2021/06/09)
The invention relates to the technical field of medicine synthesis, and particularly discloses a method for synthesizing lobeline hydrochloride. The method comprises the following steps: performing acylation reaction on ethyl acetoacetate and benzoyl chloride serving as raw materials in the presence of NaOH, NH4Cl and the like, performing hydrolysis reaction on the obtained ethyl benzoylacetate in water in the presence of potassium hydroxide to obtain benzoylacetic acid, carrying out a condensation reaction with glutaraldehyde and methylamine hydrochloride in a citric acid buffer solution, carrying out a reduction reaction on lobeline diketone hydrochloride obtained by the condensation reaction in a mixed solution composed of potassium borohydride, activated carbon, sodium hydroxide and methanol, quenching the reducing agent in the obtained reaction liquid by sulfuric acid, sequentially filtering, extracting, concentrating, cooling and crystallizing to obtain lobeline racemate, then adding L-DBTA, and sequentially performing resolution, dissociation and hydrochlorination to obtain lobeline hydrochloride. The synthesis method has the characteristics of few synthesis steps, simple synthesis conditions, convenience in operation and the like, and the used raw materials have the characteristics of wide source, low price and the like.
Double decarboxylative route to 3-substituted pyrrolidines: Reaction of monoalkyl malonates and related carboxylic acids with sarcosine and formaldehyde
Buev, Evgeny M.,Smorodina, Anastasia A.,Moshkin, Vladimir S.,Sosnovskikh, Vyacheslav Y.
supporting information, (2020/02/22)
Three-component reactions of monoalkyl malonates, cyanoacetic acids or 2-ketocarboxylic acids, N-methylglycine, and formaldehyde were developed to rapidly access 3-substituted pyrrolidines in 17–97% yield. These reactions represent a double decarboxylative domino-sequence promoted by pyrrolidine and involve N-methylazomethine ylide as the reactive intermediate.
Engineered Biosynthesis of Fungal 4-Quinolone Natural Products
Liu, Mengting,Ohashi, Masao,Tang, Yi
supporting information, p. 6637 - 6641 (2020/09/02)
Quinolone-containing natural products are widely found in bacteria, fungi, and plants. The fungal quinolactacins, which are N-methyl-4-quinolones, display a wide spectrum of biological activities. Here we uncovered a concise nonribosomal peptide synthetase pathway involved in quinolactacin A biosynthesis from Penicillium by using heterologous reconstitution and in vitro enzymatic synthesis. The N-desmethyl analog of quinolactacin A was accessed through the construction of a hybrid bacterial and fungi pathway in the heterologous host.
CO2-Folded Single-Chain Nanoparticles as Recyclable, Improved Carboxylase Mimics
Chen, Liang,Yan, Qiang,Zeng, Rongjin
supporting information, p. 18418 - 18422 (2020/08/21)
Emulating the function of natural carboxylases to convert CO2 under atmospheric condition is a great challenge. Herein we report a class of CO2-folded single-chain nanoparticles (SCNPs) that can function as recyclable, function-intensified carboxylase mimics. Lewis pair polymers containing bulky Lewis acidic and basic groups as the precursor, can bind CO2 to drive an intramolecular folding into SCNPs, in which CO2 as the folded nodes can form gas-bridged bonds. Such bridging linkages highly activate CO2, which endows the SCNPs with extraordinary catalytic ability that can not only catalyze CO2-insertion of C(sp3)-H for imitating the natural enzyme's function, it can also act on non-natural carboxylation pathways for C(sp2 and sp)-H substrates. The nanocatalysts are of highly catalytic efficiency and recyclability, and can work at room temperature and near ambient CO2 condition, inspiring a new approach to sustainable C1 utilization.
Expanding the repertoire of nitrilases with broad substrate specificity and high substrate tolerance for biocatalytic applications
Rayavarapu, Pratima,Shah, Shikha,Sunder, Avinash Vellore,Wangikar, Pramod P.
, p. 289 - 296 (2020/05/18)
Enzymatic conversion of nitriles to carboxylic acids by nitrilases has gained significance in the green synthesis of several pharmaceutical precursors and fine chemicals. Although nitrilases from several sources have been characterized, there exists a scope for identifying broad spectrum nitrilases exhibiting higher substrate tolerance and better thermostability to develop industrially relevant biocatalytic processes. Through genome mining, we have identified nine novel nitrilase sequences from bacteria and evaluated their activity on a broad spectrum of 23 industrially relevant nitrile substrates. Nitrilases from Zobellia galactanivorans, Achromobacter insolitus and Cupriavidus necator were highly active on varying classes of nitriles and applied as whole cell biocatalysts in lab scale processes. Z. galactanivorans nitrilase could convert 4-cyanopyridine to achieve yields of 1.79 M isonicotinic acid within 3 h via fed-batch substrate addition. The nitrilase from A. insolitus could hydrolyze 630 mM iminodiacetonitrile at a fast rate, effecting 86 % conversion to iminodiacetic acid within 1 h. The arylaliphatic nitrilase from C. necator catalysed enantioselective hydrolysis of 740 mM mandelonitrile to (R)-mandelic acid in 4 h. Significantly high product yields suggest that these enzymes would be promising additions to the suite of nitrilases for upscale biocatalytic application.
Synthesis of novel proxyphylline derivatives with dual Anti-Candida albicans and anticancer activity
Borowiecki, Pawe?,Wińska, Patrycja,Bretner, Maria,Gizińska, Ma?gorzata,Koronkiewicz, Miros?awa,Staniszewska, Monika
, p. 307 - 333 (2018/03/21)
Three out of 16 newly synthesized 1,3-dimethylxanthine derivatives (proxyphylline analogues) exhibited consistencies between antifungal and anticancer properties. Proxyphylline possessing 1-(10H-phenothiazin-10-yl)propan-2-yl (6) and polybrominated benzimidazole (41) or benzotriazole moiety (42) remained selectively cidal against Candida albicans (lg R ≥ 3 at conc. of 31, 36 and 20 μM, respectively) however not against normal mammalian Vero cell line in vitro (IC50 ≥ 280 μM) and Galleria mellonella in vivo. These compounds also displayed moderate antineoplastic activity against human breast adenocarcinoma (MCF-7) cell line (EC50 = 80 μM) and high against peripheral blood T lymphoblast (CCRF-CEM) (EC50 = 6.3–6.5 μM). In addition, 6 and 42 exerted: (1) dual activity against fungal adhesion and damage mature biofilm; (2) necrosis of planktonic cells due to loss of membrane function and of structural integrity; (3) biochemical (inhibition of sessile cell respiration) and morphological changes in cell wall polysaccharide contents. Therefore, leading proxyphylline derivatives can be employed to prevent cancer-associated biofilm Candida infections.
In situ generation of nitrile oxides from copper carbene and tert -butyl nitrite: Synthesis of fully substituted isoxazoles
Chen, Rongxiang,Ogunlana, Abosede Adejoke,Fang, Shangwen,Long, Wenhao,Sun, Hongmei,Bao, Xiaoguang,Wan, Xiaobing
, p. 4683 - 4687 (2018/07/06)
Herein, we present a novel [3 + 2] cycloaddition reaction of β-keto esters with nitrile oxides, which were generated in situ from copper carbene and tert-butyl nitrite. This three-component reaction provides new methodology for the direct synthesis of fully substituted isoxazole derivatives, featuring mild reaction conditions, readily accessible starting materials and simple operation. The experimental studies and DFT calculations suggest that the reaction starts with the generation of the key intermediate nitrile oxides, followed by a [3 + 2] cycloaddition reaction of β-keto esters to give the final isoxazole products.
