95416-57-2Relevant academic research and scientific papers
8-Hydroxyquinolin-2(1H)-one analogues as potential β2-agonists: Design, synthesis and activity study
Xing, Gang,Zhi, Zhengxing,Yi, Ce,Zou, Jitian,Jing, Xuefeng,Yiu-Ho Woo, Anthony,Lin, Bin,Pan, Li,Zhang, Yuyang,Cheng, Maosheng
, (2021/07/19)
β2-Agonists that bind to plasmalemmal β2-adrenoceptors causing cAMP accumulation are widely used as bronchodilators in chronic respiratory diseases. Here, we designed and synthesized a group of 8-hydroxyquinolin-2(1H)-one analogues and studied their β2-agonistic activities with a cellular cAMP assay. Compounds B05 and C08 were identified as potent (EC50 2-agonists among the compounds tested. They behaved as partial β2-agonists in non-overexpressed HEK293 cells, and possessed rapid smooth muscle relaxant actions and long duration of action in isolated guinea pig tracheal strip preparations. In summary, B05 and C08 are β2-agonists with potential applicability in chronic respiratory diseases.
Piperlongumine derivative as well as preparation method and application thereof
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Paragraph 0033; 0040; 0114-0117, (2021/01/28)
The invention discloses a Piperlongumine derivative as well as a preparation method and application thereof. The Piperlongumine derivative has the following structure: the Piperlongumine derivative provided by the invention contains a plurality of Michael addition receptor units, and the novel structure improves the electrophilicity, so that the Piperlongumine derivative has good protein targetingpotential, and the Piperlongumine derivative has a good inhibition effect on thioredoxin reductase; in an antitumor bioactive in-vitro screening experiment, the derivative also has a certain inhibition effect on the growth of tumor cells, and meanwhile, the derivative has an effect of promoting the generation of active oxygen in A549 human lung cancer cells.
Sequential Two-Step Stereoselective Amination of Allylic Alcohols through the Combination of Laccases and Amine Transaminases
Albarrán-Velo, Jesús,Lavandera, Iván,Gotor-Fernández, Vicente
, p. 200 - 211 (2019/12/03)
A sequential two-step chemoenzymatic methodology for the stereoselective synthesis of (3E)-4-(het)arylbut-3-en-2-amines in a highly selective manner and under mild reaction conditions is described. The approach consists of oxidation of the corresponding racemic alcohol precursors by the use of a catalytic system made up of the laccase from Trametes versicolor and the oxy-radical TEMPO, followed by the asymmetric reductive bio-transamination of the corresponding ketone intermediates. Optimisation of the oxidation reaction, exhaustive amine transaminase screening for the bio-transaminations and the compatibility of the two enzymatic reactions were studied in depth in search of a design of a compatible sequential cascade. This synthetic strategy was successful and the combinations of enzymes displayed a broad substrate scope, with 16 chiral amines being obtained in moderate to good isolated yields (29–75 %) and with excellent enantiomeric excess values (94 to >99 %). Interestingly, both amine enantiomers can be achieved, depending on the selectivity of the amine transaminase employed in the system.
One-pot two-step chemoenzymatic deracemization of allylic alcohols using laccases and alcohol dehydrogenases
Albarrán-Velo, Jesús,Gotor-Fernández, Vicente,Lavandera, Iván
, (2020/07/03)
A series of enantioenriched (hetero)aromatic secondary allylic alcohols has been synthesized through deracemization of the corresponding racemic mixtures combining a non-selective chemoenzymatic oxidation (laccase from Trametes versicolor and oxy-radical TEMPO) and a stereoselective biocatalyzed reduction (lyophilized cells of E. coli overexpressing an alcohol dehydrogenase, ADH). Both steps were performed in aqueous medium under very mild reaction conditions. After optimization, a sequential one-pot two-step protocol was set up, obtaining the corresponding chiral alcohols in moderate to high conversions (48–95%) and enantiomeric excess (65->99% ee). Depending on the ADH stereopreference, both antipodes from these valuable chiral synthons could be prepared, even at preparative scale (119?178 mg), in a straightforward manner.
Stereodivergent Pd/Cu Catalysis for the Dynamic Kinetic Asymmetric Transformation of Racemic Unsymmetrical 1,3-Disubstituted Allyl Acetates
He, Rui,Huo, Xiaohong,Zhao, Ling,Wang, Feijun,Jiang, Liyin,Liao, Jian,Zhang, Wanbin
supporting information, p. 8097 - 8103 (2020/05/22)
A stereodivergent Pd/Cu catalyst system has been developed for the unprecedented dynamic kinetic asymmetric transformation (DyKAT) of racemic unsymmetrical 1,3-disubstituted allylic acetates with prochiral aldimine esters. A series of α,α-disubstituted α-amino acids bearing vicinal stereocenters were easily prepared with excellent enantioselectivities (up to >99% ee) and diastereoselectivities (up to >20:1 dr). Moreover, all four stereoisomers of the product can be readily obtained simply by switching the configurations of the two chiral metal catalysts. Furthermore, the present work highlights the power of synergistic Pd/Cu catalysis consisting of two common bidentate chiral ligands for stereodivergent synthesis.
Construction of Multiple-Substituted Chiral Cyclohexanes through Hydrogenative Desymmetrization of 2,2,5-Trisubstituted 1,3-Cyclohexanediones
Yu, Chang-Bin,Song, Bo,Chen, Mu-Wang,Shen, Hong-Qiang,Zhou, Yong-Gui
supporting information, p. 9401 - 9404 (2019/11/28)
The construction of chiral multiple-substituted cyclohexanes motifs is a challenging topic in organic synthesis. By the combination of desymmetrization and remote stereocontrol, a ruthenium-catalyzed transfer hydrogenative desymmetrization of 2,2,5-trisubstituted 1,3-cyclohexanediones has been successfully developed for the construction of chiral multiple-substituted cyclohexanes with high enantioselectivity and diastereoselectivity. When an ester group was introduced to the two-position, a hydrogenative desymmetrization/transesterification cascade occurred, affording the bicyclic lactones bearing three stereocenters, including two discrete stereocenters and one quaternary stereogenic center, with high enantioselectivity. The products are the multiple-substituted chiral cyclohexanes bearing the hydroxyl and carbonyl functional groups, which provide a new opportunity for further precise elaboration.
Rh(III)-Catalyzed Enaminone-Directed Alkenyl C-H Activation for the Synthesis of Salicylaldehydes
Qi, Bing,Guo, Shan,Zhang, Wenjing,Yu, Xiaolong,Song, Chao,Zhu, Jin
supporting information, p. 3996 - 3999 (2018/07/15)
A Rh(III)-catalyzed enaminone-directed alkenyl C-H coupling with alkynes for the synthesis of salicylaldehyde derivatives is reported. This represents a unique example of benzene ring framework formation through a transition-metal-catalyzed, directed C-H activation strategy. The two incorporated reactive functionalities, aldehyde and hydroxy groups, provide convenient synthetic handles for further structural elaboration.
Synthesis of Enones and Enals via Dehydrogenation of Saturated Ketones and Aldehydes
Pan, Gao-Fei,Zhu, Xue-Qing,Guo, Rui-Li,Gao, Ya-Ru,Wang, Yong-Qiang
, p. 4774 - 4783 (2018/11/10)
A general, efficient and economic palladium-catalyzed dehydrogenation to form enones or enals has been developed. The approach possesses extremely broad substrate scope including various linear or cyclic saturated ketones and aldehydes. The protocol is ligand-free, and molecular oxygen is used as the sole clean oxidant in the reaction. Due to mild reaction conditions, good functional group compatibility, and versatile utilities of enones and enals, the method can be applied in the late-stage synthesis of natural products, pharmaceuticals and fine chemicals. (Figure presented.).
Palladium-Catalyzed Cleavage of α-Allenylic Aryl Ether toward Pyrazolemethylene-Substituted Phosphinyl Allenes and Their Transformations via Alkenyl C-P(O) Cleavage
Zhu, Jie,Mao, Mao,Ji, Huan-Jing,Xu, Jiang-Yan,Wu, Lei
supporting information, p. 1946 - 1949 (2017/04/28)
A palladium-catalyzed two-component coupling of allenylphosphine oxides with conjugated N-tosylhydrazones is revealed. For the first time, the cleavage of α-allenylic aryl ether toward pyrazolemethylene-substituted phosphinyl allenes enabled facile synthesis of combined motifs with pyrazole and allene. Moreover, the obtained adducts could be easily transformed to potential bioactive multifunctionalized phosphinates via a novel alkenyl C-P(O) cleavage.
Poly(N-isopropylacrylamide-co-l-proline)-catalyzed Claisen-Schmidt and Knoevenagel condensations: Unexpected enhanced catalytic activity of the polymer catalyst
Zhang, Hao,Han, Mengting,Chen, Tian,Xu, Lin,Yu, Lei
, p. 48214 - 48221 (2017/11/03)
The polymer catalyst is more effective than the corresponding monomer catalyst? Yes! The proline-modified polymer, poly(N-isopropylacrylamide-co-l-proline), was unexpectedly found to be more effective than the corresponding monomer l-proline catalyst in Claisen-Schmidt and Knoevenagel condensation reactions. 1H NMR, GC analysis and control reactions revealed that this abnormal phenomenon might be attributed to an enhanced concentration of the reactant on the surface of the polymer catalyst, which might be due to adsorption of the reactants to the polymer through hydrogen-bonding of the proline moiety with the reactants. This new polymer catalyst was so robust that it could be reused at least 10 times without deactivation. The polymer-catalyzed method was rather tolerant of substrates bearing sensitive groups that are usually incompatible with conventional acid- or base-catalyzed methods, reducing the protection-deprotection steps of the substrates.
