20766-37-4Relevant articles and documents
An efficient Pd@Pro-GO heterogeneous catalyst for the α, β-dehydrogenation of saturated aldehyde and ketones
Pan, Gao-Fei,Wang, Zhe,Chang, Yi-Yuan,Hao, Yue,Wang, Yi-Chen,Xing, Rui-Guang
supporting information, (2021/12/30)
An Efficient Pd@Pro-GO heterogeneous catalyst was developed that can promote the α, β-dehydrogenation of saturated aldehyde and ketones in the yield of 73% ? 92% at mild conditions without extra oxidants and additives. Pd@Pro-GO heterogeneous catalyst was synthesized via two steps: firstly, the Pro-GO was obtained by the esterification reaction between graphene oxide (GO) and N-(tert-Butoxycarbonyl)-L-proline (Boc-Pro-OH), followed by removing the protection group tert-Butoxycarbonyl (Boc), which endowed the proline-functionalized GO with both the lewis acid site (COOH) and the bronsted base site (NH), besides, the pyrrolidine of proline also can form imine with aldehydes to activate these substrates; Second, palladium was dispersed on the proline-functionalized GO (Pro-GO) to obtained heterogeneous catalyst Pd@Pro-GO. Mechanistic studies have shown that the Pd@Pro-GO-catalyzed α,β-dehydrogenation of saturated aldehyde and ketones was realized by an improved heterogeneously catalyzed Saegusa oxidation reaction. Based on the obove characteristics, the Pd@Pro-GO will be widely used in the transition metal catalytic field.
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.
Organocatalytic diastereo- And enantioselective oxa-hetero-Diels-Alder reactions of enones with aryl trifluoromethyl ketones for the synthesis of trifluoromethyl-substituted tetrahydropyrans
Pasha, Maira,Tanaka, Fujie
supporting information, p. 9242 - 9250 (2021/11/16)
Tetrahydropyran derivatives are found in bioactives, and introduction of the trifluoromethyl group into molecules often improves biofunctions. Here we report diastereo- and enantioselective oxa-hetero-Diels-Alder reactions catalyzed by amine-based catalyst systems that afford trifluoromethyl-substituted tetrahydropyranones. Catalyst systems and conditions suitable for the reactions to provide the desired diastereomer products with high enantioselectivities were identified, and various trifluoromethyl-substituted tetrahydropyranones were synthesized with high diastereo- and enantioselectivities. Mechanistic investigation suggested that the reactions involve a [4 + 2] cycloaddition pathway, in which the enamine of the enone acts as the diene and the ketone carbonyl group of the aryl trifluoromethyl ketone acts as the dienophile. In this study, tetrahydropyran derivatives with the desired stereochemistry that are difficult to synthesize by previously reported methods were concisely obtained, and the range of tetrahydropyran derivatives that can be synthesized was expanded. This journal is
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.
An access to α, β-unsaturated ketones via dual cooperative catalysis
Syamala, Lakshmi V.R. Babu,Khopade, Tushar M.,Warghude, Prakash K.,Bhat, Ramakrishna G.
supporting information, p. 88 - 91 (2018/12/05)
A dual cooperative organocatalytic approach for the synthesis of α, β-unsaturated ketones is described. This one pot transformation is realized via a domino Knoevenagel-Michael-retro Michael reaction sequence. Various aliphatic ketones reacted smoothly with aromatic as well as aliphatic aldehydes in presence catalytic amount of Meldrum's acid and bifunctional amine. The highlights of this protocol are the easy availability of catalysts, high selectivity, and functional group tolerance. The reaction proved to highly E-selective with no side products emanating from self-condensation, unlike the base-mediated reactions.
Dehydrozingerone Inspired Discovery of Potential Broad-Spectrum Fungicidal Agents as Ergosterol Biosynthesis Inhibitors
Song, Xiangmin,Zhu, Xinyue,Li, Ting,Liang, Cai,Zhang, Meng,Shao, Yu,Tao, Jun,Sun, Ranfeng
, p. 11354 - 11363 (2019/10/16)
A series of dehydrozingerone derivatives were synthesized, and their fungicidal activities and action mechanism against Colletotrichum musae were evaluated. The bioassay result showed that most compounds exhibited excellent fungicidal activity in vitro at 50 μg mL-1. Compounds 13, 16, 18, 19, and 27 exhibited broad-spectrum fungicidal activity; especially, compounds 19 and 27 were found to have more potent fungicidal activity than azoxystrobin. The EC50 values of compounds 19 and 27 against Rhizoctonia solani were 0.943 and 0.161 μg mL-1 respectively. Moreover, compound 27 exhibited significant in vitro bactericidal activity against Xanthomonas oryzae pv. oryzae, with an EC50 value of 11.386 μg mL-1, and its curative effect (49.64%) and protection effect (51.74%) on rice bacterial blight disease was equivalent to that of zhongshengmycin (42.90%, 40.80% respectively). Compound 27 could also effectively control gray mold (87.10%, 200 μg mL-1) and rice sheath blight (100%, 200 μg mL-1 82.89%, 100 μg mL-1) in vivo. Preliminary action mechanism study showed that compound 27 mainly acted on the cell membrane and significantly inhibited ergosterol biosynthesis in Colletotrichum musae.
Dehydrozingerone derivative and preparation method and application thereof
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Paragraph 0084-0087; 0088; 0090, (2019/11/20)
The invention provides a dehydrozingerone derivative as shown in the description. R-R are each independently selected from hydrogen or halogen or a nitro group or an alkyl group or a substitutedalkoxy group or an alkoxy group or a hydroxyl group; the substituent in the substituted alkoxy group is selected from one or multiple of halogen, a nitro group and a hydroxyl group; R and R areeach independently selected from hydrogen or halogen or nitrogen-containing heterocycle; R is selected from an alkyl group or an alkoxy group or a substituted alkoxy group; the substituent in thesubstituted alkyl group is selected from one or multiple of halogen, a nitro group and a hydroxyl group; X is selected from a hetero atom or a hydroxylamine group. The dehydrozingerone derivative hasbroad-spectrum activity against plant pathogenic fungi and bacteria, and has certain nematicidal activity, and is a lead compound with the broad biological activity.
Evaluation of sulphonamide derivatives acting as inhibitors of human carbonic anhydrase isoforms I, II and Mycobacterium tuberculosis β-class enzyme Rv3273
Wani, Tanvi V.,Bua, Silvia,Khude, Pravin S.,Chowdhary, Abdul H.,Supuran, Claudiu T.,Toraskar, Mrunmayee P.
, p. 962 - 971 (2018/05/29)
A series of novel sulphonamide derivatives was obtained from sulphanilamide which was N4-alkylated with ethyl bromoacetate followed by reaction with hydrazine hydrate. The hydrazide obtained was further reacted with various aromatic aldehydes. The novel sulphonamides were characterised by infrared, mass spectrometry, 1H- and 13C-NMR and purity was determined by high-performance liquid chromatography (HPLC). Human (h) carbonic anhydrase (CA, EC 4.2.1.1) isoforms hCA I and II and Mycobacterium tuberculosis β-CA encoded by the gene Rv3273 (mtCA 3) inhibition activity was investigated with the synthesised compounds which showed promising inhibition. The KIs were in the range of 54.6 nM–1.8 μM against hCA I, in the range of 32.1 nM–5.5 μM against hCA II and of 127 nM–2.12 μM against mtCA 3.
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.
Traceless OH-Directed Wacker Oxidation-Elimination, an Alternative to Wittig Olefination/Aldol Condensation: One-Pot Synthesis of α,β-Unsaturated and Nonconjugated Ketones from Homoallyl Alcohols
Bethi, Venkati,Fernandes, Rodney A.
, p. 8577 - 8584 (2016/09/28)
A new method for one-pot synthesis of β-substituted and β,β-disubstituted α,β-unsaturated methyl ketones from homoallyl alcohols by sequential PdCl2/CrO3-promoted Wacker process followed by an acid-mediated dehydration reaction has been developed. Remarkably, internal homoallyl alcohols delivered regioselectively nonconjugated unsaturated carbonyl compounds under the same protocol. A new starting material-based synthesis of α,β-unsaturated and nonconjugated methyl ketones is demonstrated.
