- Facile preparation of optically pure diamines and their applications in asymmetric aldol reactions
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A family of optically pure diamines with tertiary-primary amine motif has been synthesized from optically pure binaphthol and amino acids. The catalysts are highly tunable in structure and has demonstrated high efficiency in direct aldol reactions. Thus, a variety of aldehydes or methyl 2-oxoacetates reacted with acetone in the presence of 10 mol % of catalyst and 20 mol % TFA, furnishing the desired alcohols in up to 99% yield with excellent enantioselectivities (up to 96% ee).
- Liu, Quan-Zhong,Wang, Xue-Lian,Luo, Shi-Wei,Zheng, Bao-Lei,Qin, Da-Bin
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Read Online
- An efficient Pd@Pro-GO heterogeneous catalyst for the α, β-dehydrogenation of saturated aldehyde and ketones
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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.
- Pan, Gao-Fei,Wang, Zhe,Chang, Yi-Yuan,Hao, Yue,Wang, Yi-Chen,Xing, Rui-Guang
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supporting information
(2021/12/30)
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- 8-Hydroxyquinolin-2(1H)-one analogues as potential β2-agonists: Design, synthesis and activity study
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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.
- Xing, Gang,Zhi, Zhengxing,Yi, Ce,Zou, Jitian,Jing, Xuefeng,Yiu-Ho Woo, Anthony,Lin, Bin,Pan, Li,Zhang, Yuyang,Cheng, Maosheng
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- Organocatalytic diastereo- And enantioselective oxa-hetero-Diels-Alder reactions of enones with aryl trifluoromethyl ketones for the synthesis of trifluoromethyl-substituted tetrahydropyrans
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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
- Pasha, Maira,Tanaka, Fujie
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supporting information
p. 9242 - 9250
(2021/11/16)
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- Stereodivergent Pd/Cu Catalysis for the Dynamic Kinetic Asymmetric Transformation of Racemic Unsymmetrical 1,3-Disubstituted Allyl Acetates
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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.
- He, Rui,Huo, Xiaohong,Zhao, Ling,Wang, Feijun,Jiang, Liyin,Liao, Jian,Zhang, Wanbin
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supporting information
p. 8097 - 8103
(2020/05/22)
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- Dehydrozingerone Inspired Discovery of Potential Broad-Spectrum Fungicidal Agents as Ergosterol Biosynthesis Inhibitors
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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.
- Song, Xiangmin,Zhu, Xinyue,Li, Ting,Liang, Cai,Zhang, Meng,Shao, Yu,Tao, Jun,Sun, Ranfeng
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p. 11354 - 11363
(2019/10/16)
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- An access to α, β-unsaturated ketones via dual cooperative catalysis
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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.
- Syamala, Lakshmi V.R. Babu,Khopade, Tushar M.,Warghude, Prakash K.,Bhat, Ramakrishna G.
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supporting information
p. 88 - 91
(2018/12/05)
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- Dehydrozingerone derivative and preparation method and application thereof
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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.
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Paragraph 0084-0087; 0088; 0090
(2019/11/20)
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- Evaluation of sulphonamide derivatives acting as inhibitors of human carbonic anhydrase isoforms I, II and Mycobacterium tuberculosis β-class enzyme Rv3273
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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.
- Wani, Tanvi V.,Bua, Silvia,Khude, Pravin S.,Chowdhary, Abdul H.,Supuran, Claudiu T.,Toraskar, Mrunmayee P.
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p. 962 - 971
(2018/05/29)
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- Poly(N-isopropylacrylamide-co-l-proline)-catalyzed Claisen-Schmidt and Knoevenagel condensations: Unexpected enhanced catalytic activity of the polymer catalyst
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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.
- Zhang, Hao,Han, Mengting,Chen, Tian,Xu, Lin,Yu, Lei
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p. 48214 - 48221
(2017/11/03)
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- Enzyme-catalyzed domino reaction: Efficient construction of spirocyclic oxindole skeleton using porcine pepsin
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Pepsin from porcine gastric mucosa was used as a sustainable and environmentally friendly biocatalyst in the domino Knoevenagel/Michael/Michael reaction for the synthesis of spirooxindole derivatives in methanol. A wide range of isatins and α,β-unsaturated ketones reacting with malononitrile provided the corresponding products in yields of up to 99% with diastereoselectivities of up to >99:1 dr. This pepsin-catalyzed domino reaction provided a novel case of enzyme catalytic promiscuity.
- He, Yan-Hong,He, Tao,Guo, Jun-Tao,Li, Rui,Xiang, Yang,Yang, Da-Cheng,Guan, Zhi
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p. 2239 - 2248
(2016/04/26)
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- Method for preparing alpha and beta-unsaturated ketone
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The invention provides a method for preparing alpha and beta-unsaturated ketone. The method includes that L-proline is used as a catalyst, secondary amine is used as a cocatalyst, and the alpha and beta-unsaturated ketone can be directly synthesized in alcohol or ketone solution by means of aldol condensation under neutral conditions at one step. Compared with the traditional method, the method has the advantages that raw materials are easily available, the method is low in cost and is environmental friendly, reaction conditions are mild, solvents are clean and environmental friendly, equipment can be protected against corrosion under the neutral conditions, the catalyst is high in acid resistance, and the method is applicable to industrial production.
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Paragraph 0012; 0013; 0034; 0035; 0036; 0040; 0041
(2016/10/31)
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- 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
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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.
- Bethi, Venkati,Fernandes, Rodney A.
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p. 8577 - 8584
(2016/09/28)
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- Copper-catalyzed retro-aldol reaction of β-hydroxy ketones or nitriles with aldehydes: Chemo- and stereoselective access to (E)-enones and (E)-acrylonitriles
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A copper-catalyzed transfer aldol type reaction of β-hydroxy ketones or nitriles with aldehydes is reported, which enables chemo- and stereoselective access to (E)-α,β-unsaturated ketones and (E)-acrylonitriles. A key step of the in situ copper(i)-promoted retro-aldol reaction of β-hydroxy ketones or nitriles is proposed to generate a reactive Cu(i) enolate or cyanomethyl intermediate, which undergoes ensuing aldol condensation with aldehydes to deliver the products. This reaction uses 1.2 mol% Cu(IPr)Cl (IPr denotes 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) as the catalyst in the presence of 6.0 mol% NaOtBu cocatalyst at room temperature or 70 °C. A range of aryl and heteroaryl aldehydes as well as acrylaldehydes are compatible with many useful functional groups being tolerated. Under the mild and weakly basic conditions, competitive Cannizzaro-type reaction of benzaldehydes and side reactions of base-sensitive functional groups can be effectively suppressed, which show synthetic advantages of this reaction compared to classic aldol reactions. The synthetic potential of this reaction is further demonstrated by the one-step synthesis of biologically active quinolines and 1,8-naphthyridine in excellent yields (up to 91%). Finally, a full catalytic cycle for this reaction has been constructed using DFT computational studies in the context of a retro-aldol/aldol two-stage mechanism. A rather flat reaction energy profile is found indicating that both stages are kinetically facile, which is consistent with the mild reaction conditions.
- Zhang, Song-Lin,Deng, Zhu-Qin
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p. 7282 - 7294
(2016/08/05)
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- Organoselenium-catalyzed baeyer-villiger oxidation of α,β-unsaturated ketones by hydrogen peroxide to access vinyl esters
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By carefully screening the organoselenium pre-catalysts and optimizing the reaction conditions, simple dibenzyl diselenide was found to be the best pre-catalyst for Baeyer-Villiger oxidation of (E)-α,β-unsaturated ketones with the green oxidant hydrogen peroxide at room temperature. The organoselenium catalyst used in this reaction could be recycled and reused several times. This new method was suitable not only for methyl unsaturated ketones, but also for alkyl and aryl unsaturated ketones. Therefore, it provided a direct, mild, practical, highly functional group-tolerant process for the chemoselective preparation of the versatile (E)-vinyl esters from the readily available (E)-α,β-unsaturated ketones. A possible mechanism was also proposed to rationalize the activity of the organoselenium catalyst in the presence of hydrogen peroxide in this Baeyer-Villiger oxidation reaction.
- Zhang, Xu,Ye, Jianqing,Yu, Lei,Shi, Xinkang,Zhang, Ming,Xu, Qing,Lautens, Mark
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supporting information
p. 955 - 960
(2015/03/30)
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- Synthesis of new 4-phenylpyrimidine-2(1H)-thiones and their potency to inhibit COX-1 and COX-2
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Several new 4-phenylpyrimidine-2(1H)-thiones have been prepared and investigated for their potencies to inhibit COX-1 and COX-2 enzymes, and COX-2 expression in THP-1 cells. Structure-activity-relationships and physicochemical parameters are discussed. Pharmacophore screening and docking studies were carried out for the most active compound.
- Seebacher, Werner,Faist, Johanna,Presser, Armin,Weis, Robert,Saf, Robert,Kaserer, Teresa,Temml, Veronika,Schuster, Daniela,Ortmann, Sabine,Otto, Nadine,Bauer, Rudolf
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p. 552 - 559
(2015/07/27)
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- FUSED THIOPHENE AND THIAZOLE DERIVATIVES AS ROR GAMMA MODULATORS
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The present invention provides fused thiophene and thiazole derivatives of formula (I), which may be therapeutically useful, more particularly as RORγ modulators; in which R1, R2, R3, R4, R5, R6, R7, X1, X2, L, m, n and ring A have the meanings given in the specification, and pharmaceutically acceptable salts thereof that are useful in the treatment and prevention of diseases or disorders, in particular their use in disease(s) or disorder(s) where there is an advantage in modulating RORγ receptor. The present invention also provides preparation of the compounds and pharmaceutical formulations comprising at least one of the fused thiophene and thiazole derivatives of formula (I), together with a pharmaceutically acceptable carrier, diluent or excipient therefor.
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Page/Page column 107
(2015/07/16)
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- Synthesis of Polysubstituted Pyridines via a One-Pot Metal-Free Strategy
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An efficient strategy for the one-pot synthesis of polysubstituted pyridines via a cascade reaction from aldehydes, phosphorus ylides, and propargyl azide is reported. The reaction sequence involves a Wittig reaction, a Staudinger reaction, an aza-Wittig reaction, a 6π-3-azatriene electrocyclization, and a 1,3-H shift. This protocol provides quick access to the polysubstituted pyridines from readily available substrates in good to excellent yields.
- Wei, Hongbo,Li, Yun,Xiao, Ke,Cheng, Bin,Wang, Huifei,Hu, Lin,Zhai, Hongbin
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supporting information
p. 5974 - 5977
(2016/01/09)
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- Catalytic microwave-promoted direct aldol condensation using resin-bound secondary amine
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A series of polystyrene-supported imino group-bearing catalysts were prepared. A highly efficient combination of recyclable catalysts and microwave irradiation was developed as a green protocol for the direct aldol reaction. Notably, microwaves greatly shorten the reaction times to only 20 min and improve the yield significantly. Catalyst loading was reduced as well. Different aromatic aldehydes as aldol donors were subjected to our catalyst system and afforded the corresponding products in satisfactory yields. Additionally, the polymer-supported catalysts could be recovered by simple filtration and were reusable for at least four times without significant loss of reactivity. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the following free supplemental resource(s): Full experimental and spectral details.]
- Liao, Fu Xu,Wang, Yu Guang,Zhu, Qing
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supporting information
p. 161 - 169
(2013/12/04)
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- Palladium-catalyzed conjugate addition of arylsulfonyl hydrazides to α,β-unsaturated ketones
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A palladium-catalyzed desulfitative-denitrogenative conjugate addition of arylsulfonyl hydrazides to α,β-unsaturated ketones is described. The reaction showed very good selectivity and tolerated a wide range of functionalities under an atmosphere of oxygen with or without the aid of a metal co-oxidant. The Royal Society of Chemistry 2013.
- Chen, Wen,Chen, Hui,Xiao, Fuhong,Deng, Guo-Jun
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supporting information
p. 4295 - 4298
(2013/08/23)
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- Synthesis of β-fluoroenones and their reductive rearrangement in aqueous media
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In this paper, a simple and efficient preparation of β-fluoroenones, as a mixture of E/Z isomers with the E-isomer as the main product, from 1,2-allenic ketones by using TBAF·3H2O in water as a nucleophilic fluorination agent has been developed. Moreover, in exploring the synthetic applications of β-fluoroenones, an unprecedented reductive defluorination rearrangement of β-fluoroenones toward enones under mild conditions in aqueous media was also discovered.
- He, Yan,Shen, Nana,Fan, Xuesen,Zhang, Xinying
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p. 8818 - 8823
(2013/09/23)
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- Cu(OAc)2/TFA-promoted formal [3 + 3] cycloaddition/oxidation of enamines and enones for synthesis of multisubstituted aromatic amines
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New strategies for the oxidative cycloaddition of enones with enamines are developed. These cycloaddition reactions directly afford substituted aromatic amines, which are important in organic chemistry, in moderate to good yield. Cu(OAc)2/TFA is shown to be essential to achieve high reaction efficiency.
- Li, Liang,Zhao, Mi-Na,Ren, Zhi-Hui,Li, Jian-Li,Guan, Zheng-Hui
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supporting information; experimental part
p. 3506 - 3509
(2012/08/08)
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- Cyclohexane 1,3-diones and their inhibition of mutant SOD1-dependent protein aggregation and toxicity in PC12 cells
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Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of motor neurons. Currently, there is only one FDA-approved treatment for ALS (riluzole), and that drug only extends life, on average, by 2-3 months. Mutations in Cu/Zn superoxide dismutase (SOD1) are found in familial forms of the disease and have played an important role in the study of ALS pathophysiology. On the basis of their activity in a PC12-G93A-YFP high-throughput screening assay, several bioactive compounds have been identified and classified as cyclohexane-1,3-dione (CHD) derivatives. A concise and efficient synthetic route has been developed to provide diverse CHD analogs. The structural modification of the CHD scaffold led to the discovery of a more potent analog (26) with an EC50 of 700 nM having good pharmacokinetic properties, such as high solubility, low human and mouse metabolic potential, and relatively good plasma stability. It was also found to efficiently penetrate the blood-brain barrier. However, compound 26 did not exhibit any significant life span extension in the ALS mouse model. It was found that, although 26 was active in PC12 cells, it had poor activity in other cell types, including primary cortical neurons, indicating that it can penetrate into the brain, but is not active in neuronal cells, potentially due to poor selective cell penetration. Further structural modification of the CHD scaffold was aimed at improving global cell activity as well as maintaining potency. Two new analogs (71 and 73) were synthesized, which had significantly enhanced cortical neuronal cell permeability, as well as similar potency to that of 26 in the PC12-G93A assay. These CHD analogs are being investigated further as novel therapeutic candidates for ALS.
- Zhang, Wei,Benmohamed, Radhia,Arvanites, Anthony C.,Morimoto, Richard I.,Ferrante, Robert J.,Kirsch, Donald R.,Silverman, Richard B.
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experimental part
p. 1029 - 1045
(2012/03/09)
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- Anomalous Z-isomer content in Wittig reaction products from keto-stabilised ylides with ortho-heteroatom substituted benzaldehydes
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Wittig reaction products of keto-stabilised ylides with ortho-substituted benzaldehydes are found to show significantly higher than expected Z-alkene content (up to 50%) compared to analogous reactions of the same ylides with benzaldehyde itself. A cooperative effect is seen whereby the unusual Z-content is further augmented if the ylide bears greater steric bulk in the α′-position. These results are consistent with our previous observations on reactions of all ylide types with aldehydes bearing a β-heteroatom. Significantly, the cooperative effect, previously seen only with semi-stabilised ylides, has now been extended to stabilised ylides. Both the anomalous increase in Z-content and the cooperative effect can be rationalised within the [2+2] cycloaddition mechanism of the Wittig reaction.
- Byrne, Peter A.,Higham, Lee J.,McGovern, Pádraic,Gilheany, Declan G.
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supporting information
p. 6701 - 6704
(2013/01/15)
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- Asymmetric synthesis of multi-substituted spiro[5,5]undecane-1,5,9-triones via organocatalytic three-component reaction
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The asymmetric domino three-component Knoevanagel-Diels-Alder addition (ATCDA) reaction, as an important methodology, has been utilized to construct complex product from ordinary starting materials. In this report, many typical organoamine catalysts were investigated to achieve highly efficient asymmetric three-component reaction of enones 2, aldehydes 3 and Meldrum's acid 4. Various pharmacological multi-substituted spiro[5,5]undecane-1,5,9-triones promoted by 9-amino-9-deoxy-epi-quinine 1 g in one-pot, were obtained in moderate to good yields (up to 81%) with excellent diastereo-(>99:1 dr) and enantioselectivities (up to 97% ee). Meanwhile, based on the controlled experiments and analytical data, a reasonable mechanism of dual-activity for this reaction has been proposed.
- Shi, Jian,Liu, Yangbin,Wang, Min,Lin, Lili,Liu, Xiaohua,Feng, Xiaoming
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supporting information; experimental part
p. 1781 - 1787
(2011/04/15)
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- A tandem Aldol condensation/dehydration co-catalyzed by acylase and N-heterocyclic compounds in organic media
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A tandem Aldol condensation/dehydration of aldehydes and ketones could be performed under d-aminoacylase and N-heterocyclic compounds used as co-catalyst in organic media. Some control experiments have been designed to demonstrate that either acylase or N-heterocyclic compounds could not catalyze the tandem reaction. The acylase showed the highest activity in the presence of imidazole and has been used to catalyze the tandem Aldol condensation/dehydration between different aldehydes and ketones. This method has provided a new strategy to perform the tandem Aldol condensation/dehydration and expanded the application of biocatalysts.
- Chen, Xiang,Liu, Bo-Kai,Kang, Hong,Lin, Xian-Fu
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experimental part
p. 71 - 76
(2011/07/07)
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- A simple and efficient synthesis of pyrazoles in water
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A simple, highly efficient, and environmentally friendly method for the synthesis of substituted 1H-pyrazoles by one-pot condensation reaction of α,β-unsaturated carbonyl compounds with tosyl hydrazide in water was developed. The reaction system exhibited tolerance with various functional groups, Aromatic moiety with both electron-rich and electron-deficient substituents could give desired products in good to excellent yields.
- Wen, Jun,Fu, Yun,Zhang, Ruo-Yi,Zhang, Ji,Chen, Shan-Yong,Yu, Xiao-Qi
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supporting information; experimental part
p. 9618 - 9621
(2011/12/14)
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- Novel 2-(benzo[d]thiazol-2-yl)-1-(3-methyl-5-substituted-phenyl-4,5- dihydropyrazol-1-yl)ethanone Derivatives: Synthesis and antibacterial activity
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A series of novel 2-(benzo[d]thiazol-2-yl)-1-(3-methyl-5-substituted- phenyl-4,5-dihydropyrazol-1-yl)ethanone derivatives were synthesized and characterized by NMR, ESI-MS. Biological activity tests results show that compounds 4a, 4b, 4d and 4g displayed activity with MIC of 1.562 ?g/mL against B. subtilis ATCC 6633, compound 4d displayed significant activity with MIC of 1.562 μg/mL against S. aureus ATCC 6538. Compound 4a with potent antibacterial activities strongly inhibited S. aureus DNA gyrase and B. subtilis DNA gyrase with IC50s of 0.5 μg/ml against S. aureus DNA gyrase and B. subtilis DNA gyrase.
- Pan, Chun-Xiu,Lia, Jun,Liu, Xin-Hua
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scheme or table
p. 459 - 463
(2012/06/15)
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- Novel antimalarial 3-azabicyclo[3.2.2]nonane derivatives
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The present invention relates to novel 3-azabicyclo[3.2.2]nonane derivatives of the general formula (I) or a pharmaceutically acceptable salt thereof wherein R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 are as defined in the specification. The novel 3-azabicyclo[3.2.2]nonane derivatives are particularly useful for treatment and prevention of malaria and trypanosomiasis.
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- Chemoselective conjugate reduction of α,β-unsaturated ketones catalyzed by rhodium amido complexes in aqueous media
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Although a notable feature of Noyori's Ru-TsDPEN complex is that the transfer hydrogenation reaction is highly chemoselective for the C-O functional group and tolerant of alkenes, our early report indicated that the chemoselectivity could be switched from C-O to C-C bonds in the transfer hydrogenation of activated α,β-unsaturated ketones. Now we have found that a variety of α,β-unsaturated ketones, even without other electron-withdrawing functional groups, could be reduced on the alkenic double bonds with high selectivities employing amido-rhodium hydride complex in aqueous media, and up to 100% chemoselectivity has been achieved. It is notable that the chemoselectivity was improved significantly on going from organic solvent to water. Moreover, a 1,4-addition mechanism has been proposed on the basis of the corresponding experimental details and computational analysis.
- Li, Xuefeng,Li, Liangchun,Tang, Yuanfu,Zhong, Ling,Cun, Linfeng,Zhu, Jin,Liao, Jian,Deng, Jingen
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supporting information; experimental part
p. 2981 - 2988
(2010/07/05)
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- An Environment-friendly and efficient method for aldol condensation catalyzed by L-Lysine in pure water
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This is a new example of a nonmetallic small-molecule catalyst for direct intermolecular aldol reactions. We found L-lysine is an effective catalyst for this condensation between unmodified acetone and a variety of aldehydes in the presence of pure water. This green catalyst system could be reused.
- Zhang, Yan,Wang, Man Gang,Liang, Jun,Shang, Zhi Cai
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scheme or table
p. 27 - 31
(2010/08/07)
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- Enantiomerically pure allylic alcohols: preparation by Candida parapsilosis ATCC 7330 mediated deracemisation
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Biocatalytic deracemisation of racemic allylic alcohols by whole cells of Candida parapsilosis ATCC 7330 resulted in the formation of the (R)-enantiomers in high enantiomeric excesses (up to >99%) and isolated yields (up to 79%).
- Titu, Devamani,Chadha, Anju
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p. 1698 - 1701
(2008/12/20)
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- Substituted 3-phenylpropenoates and related analogs: Electron ionization mass spectral fragmentation and density functional theory calculations
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Analysis of ethyl 3-(2-chlorophenyl)propenoate by electron ionization mass spectrometry showed the distinct loss of an ortho chlorine. To characterize the structural requisites for the observed mass fragmentation, a series of 30 halogen-substituted 3-phenylpropenoate-related structures were examined. All ester-containing alkene derivatives exhibited loss of the distinctive chlorine from the 2-position of the phenyl ring. Analogous derivatives with the halogen (chlorine or bromine) in the para position did not evidence selective halogen loss. Results demonstrated that substituted 3-phenylpropenoates and their analogs fragment via the formation of a previously reported benzopyrylium intermediate. To understand the correlation between the intramolecular radical substitution and the abundance and selectivity of the chlorine (or other halogen) displacement, density functional theory calculations were performed to determine the charge on the principal cation involved in the chlorine loss (in the ortho, meta, and para positions), the charge for the neutral radical (noncation), the excess alpha-electron density on the relevant atom and the energy to form the cation from the neutral atom (ionization energy). Results showed that the selectivity and extent of halogen displacement correlated highly to the electrophilicity of the radical cation as well as the neutral radical. These data further support the proposed fragmentation mechanism involving intramolecular radical elimination. Copyright
- Wheelock,Colvin,Sanborn,Hammock
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scheme or table
p. 1053 - 1062
(2009/07/04)
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- A catalytic, highly stereoselective aldehyde olefination reaction
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A catalytic aldehyde olefination reaction has been discovered. A Cu(II) complex (5 mol %) derived from a salen-quinine mixed ligand catalyzed the reaction between aldehydes and two molecules of acetyl chloride to produce trans C-C double bonds exclusively. The new catalytic aldehyde alkenation reaction presumably goes through a C-3 acylated β-lactone intermediate that loses one molecule of CO2.
- Lin, Yun-Ming,Li, Zhongtao,Casarotto, Virginie,Ehrmantraut, Jessica,Nguyen, Annie N.
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p. 5531 - 5534
(2008/02/13)
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- Application of high pressure, induced by water freezing, to the direct asymmetric aldol reaction
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High pressure, induced by water freezing, has been successfully applied to the direct catalytic asymmetric aldol reaction, in which higher yield and better enantioselectivity can be realized than in the reaction at room temperature under 0.1MPa.
- Hayashi, Yujiro,Tsuboi, Wataru,Shoji, Mitsuru,Suzuki, Noriyuki
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p. 4353 - 4356
(2007/10/03)
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- PERNASAL PREPARATIONS
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A nasal preparation comprising a compound represented by the formula: wherein Ring A is an optionally substituted 5- or 6-membered aromatic heterocyclic ring, Ring B is an optionally substituted 5- or 6-membered aromatic homocyclic or heterocyclic ring, R
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- Substituted guanidine derivatives and process for producing the same
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A compound represented by the general formula (1): wherein each of R1, R2, R3, R4and R5is a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a saturated heterocyclic group, an aromatic group, an acyl group or the like; each of Y1, Y2, Y3and Y4is a single bond, —CH2—, —O—, —CO— or the like, provided that at least two of Y1through Y4are independently a group other than a single bond; and Z may be absent, or one or more Zs may be present and are independently an alkyl group, a substituted alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a saturated heterocyclic group, a halogen atom, a carboxyl group, an alkoxycarbonyl group, an aromatic group, an acyl group or the like, is useful as a therapeutic or prophylactic agent for diseases caused by the acceleration of the sodium/proton exchange transport system.
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Page column 67-68
(2010/01/31)
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- Aminoguanidine hydrazone derivatives, process for producing the same and drugs thereof
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The present invention is to provide a compound of the formula: wherein the ring A is an optionally substituted 5- to 6-membered aromatic heterocyclic ring, the ring B an optionally substituted 5- to 6-membered aromatic homocyclic ring or an optionally sub
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Page column 66 - 67
(2010/11/29)
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- Unsaturated oxime ethers and their use as fungicides and insecticides
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Compounds with fungicidal and insecticidal properties having formula wherein X is N or CH; Y is O, S or NR6; A is independently hydrogen, halo, cyano, (C1-C12)alkyl, or (C1-C12)alkoxy; R1and R6is independently hydrogen or (C1-C4)alkyl; R2is independently hydrogen, (C1-C12)alkyl, halo(C1-C12)alkyl, (C3-C7)cycloalkyl, (C2-C8)alkenyl, halo(C2-C8)alkenyl, (C2-C8)alkynyl, halo(C2-C8)alkynyl, aryl, aralkyl, heterocyclic, or heterocyclic(C1-C4)alkyl; R3is independently hydrogen or (C1-C4)alkyl; R4and R5is independently hydrogen, (C1-C4)alkyl, aryl, aralkyl, aryl(C2-C8)alkenyl, aryl(C2-C8)alkynyl, heterocyclic, or heterocyclic(C1-C4)alkyl wherein if one of R4and R5is hydrogen or (C1-C4)alkyl than the other of R4and R5is other than hydrogen or (C1-C4)alkyl, and its enantiomers and stereoisomers and agronomically acceptable salts.
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- Microwave induced formation of 3-chloro-5-arylpenta-2,4,-dien-1-als and 3-chloro-(5-formylaryl)penta-2,4-dien-1-als by Vilsmeier reaction
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The 3-chloro-5-arylpenta-2,4-dien-1-als and 3-chloro-(5-formylaryl)penta-2,4-dien-1-als have been prepared by Vilsmeier reaction under microwave condition. The compounds are obtained within a short duration of time (40 sec.(2.45 GHz)). The rate of the reaction is found to be accelerated by about 270 fold when compared to conventional technique. The formylated products are chromatographed and characterized by IR, 1H NMR, and 13C NMR.
- Dinakaran,Perumal
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p. 135 - 136
(2007/10/03)
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- Cyclic Amidines Part 27. An Unambiguous Synthesis of 5,10,14c-Triazabenzo naphthanthracene by a Palladium Catalysed Cyclodehalogenation
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An unambiguous route to the title triazabenzonaphthanthracene (5) is reported via a palladium-catalyzed cyclodehalogenation of the 6-chloro-7-(2-chlorobenzylidene)-benzanthracene (10) avoiding high temperature reactions and the possibility of skeletal rea
- Upton, Christopher
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p. 951 - 965
(2007/10/02)
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- Synthesis and Antimalarial Properties of 1-Imino Derivatives of 7-Chloro-3-substituted-3,4-dihydro-1,9(2H,10H)-acridinediones and Related Structures
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To improve upon the activity and properties of the 3-aryl-7-chloro-3,4-dihydro-1,9(2H,10H)-acridinediones, a variety of 1-imino derivatives (3) were prepared and shown to be highly active antimalarial agents in both rodents and primates.Among structural modifications prepared, including N10-alkyl and C2-substituted analogs, removal of the C9 oxygen, and introduction of an imino side chain at C9, the imines of the N10-H acridinediones were the most active compounds obtained.The imino derivative of7-chloro-3-(2,4-dichlorophenyl)-3,4-dihydro-1,9(2H,10H)-acridinedione (9aa) proved to be highly active in advanced studies in primates.
- Kesten, Stephen J.,Degnan, Margaret J.,Hung, Jocelyn,McNamara, Dennis J.,Ortwine, Daniel F.,et al.
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p. 3429 - 3447
(2007/10/02)
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- 5-Phenyl-2,4-pentadien-1-amines and method for inhibiting prostaglandin dehydrogenase
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5-Phenyl-2,4-pentadien-1-amines and salts thereof are provided having the structure STR1 wherein R1 is hydrogen, lower alkyl, lower alkoxy, hydroxy, lower alkanoyloxy, nitro, cyano, amino, carboxy or lower alkoxycarbonyl, and R2 and R3 are the same or different and are hydrogen, lower alkyl, alkenyl-lower alkyl, aralkyl, and substituted lower alkyl. These compounds possess useful pharmceutical activites due to their ability to inhibit the prostaglandin-inactivating enzyme 15-α-hydroxyprostaglandin dehydrogenase.
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