- Polysubstituted Indole Synthesis via Palladium/Norbornene Cooperative Catalysis of Oxime Esters
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Polysubstituted indoles are prevalent in pharmaceuticals, agrochemicals, and organic materials. Presented herein is the fact that polyfunctionalized indoles can be efficiently constructed from easily accessible oxime esters and aryl iodides, involving a palladium/norbornene synergistic synthesis. The reaction is enabled by a unique class of electrophiles in palladium/norbornene cooperative catalysis, which are oxime esters derived from simple ketone. The broad substrate scope and high functional group tolerance could make this method attractive for the synthesis of polysubstituted indoles.
- Liu, Jiechun,Lin, Haojiang,Jiang, Huanfeng,Huang, Liangbin
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supporting information
p. 484 - 489
(2022/01/20)
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- Novel substituted 5-methyl-4-acylaminoisoxazoles as antimitotic agents: Evaluation of selectivity to LNCaP cancer cells
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A series of novel antimitotic agents was designed using the replacement of heterocyclic cores in two tubulin-targeting lead molecules with the acylated 4-aminoisoxazole moiety. Target compounds were synthesized via heterocyclization of β-aryl-substituted vinylketones by tert-butyl nitrite in the presence of water as a key step. 4-Methyl-N-[5-methyl-3-(3,4,5-trimethoxyphenyl)isoxazol-4-yl]benzamide (1aa) was found to stimulate partial depolymerization of microtubules of human lung carcinoma A549 cells at a high concentration of 100 μM and to totally inhibit cell growth (IC50 = 0.99 μM) and cell viability (IC50 = 0.271 μM) in the nanomolar to submicromolar concentration range. These data provide evidence of the multitarget profile of the cytotoxic action of compound 1aa. The SAR study demonstrated that the 3,4,5-trimethoxyphenyl residue is the key structural parameter determining the efficiency both towards tubulin and other molecular targets. The cytotoxicity of 3-methyl-N-[5-methyl-3-(3,4,5-trimethoxyphenyl)isoxazol-4-yl]benzamide (1ab) to the androgen-sensitive human prostate adenocarcinoma cancer cell line LNCaP (IC50 = 0.301 μM) was approximately one order of magnitude higher than that to the conditionally normal cells lines WI-26 VA4 (IC50 = 2.26 μM) and human umbilical vein endothelial cells (IC50 = 5.58 μM) and significantly higher than that to primary fibroblasts (IC50 > 75 μM).
- Averina, Elena B.,Bunev, Alexander S.,Gracheva, Yulia A.,Grishin, Yuri K.,Kuznetsov, Sergei A.,Kuznetsova, Tamara S.,Milaeva, Elena R.,Palyulin, Vladimir A.,Radchenko, Eugene V.,Sadovnikov, Kirill S.,Shevtsov, Pavel N.,Shevtsova, Elena F.,Shtil, Alexander A.,Vasilenko, Dmitry A.,Vasilichin, Vladislav A.,Zefirov, Nikolay A.,Zefirova, Olga N.
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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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- Piperlongumine derivative as well as preparation method and application thereof
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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.
- -
-
Paragraph 0033; 0040; 0069-0072
(2021/01/28)
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- Design, green synthesis, antioxidant activity screening, and evaluation of protective effect on cerebral ischemia reperfusion injury of novel monoenone monocarbonyl curcumin analogs
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Antioxidants with high efficacy and low toxicity have the potential to treat cerebral ischemia reperfusion injury (CIRI). Dienone monocarbonyl curcumin analogs (DMCA) capable of overcoming the instability and pharmacokinetic defects of curcumin possess notable antioxidant activity but are found to be significantly toxic. In this study, a novel skeleton of the monoenone monocarbonyl curcumin analogue sAc possessing reduced toxicity and improved stability was designed on the basis of the DMCA skeleton. Moreover, 32 sAc analogs were obtained by applying a green, simple, and economical synthetic method. Multiple sAc analogs with an antioxidant protective effect in PC12 cells were screened using an H2O2-induced oxidative stress damage model, and quantitative evaluation of structure–activity relationship (QSAR) model with regression coefficient of R2 = 0.918921 was built through random forest algorithm (RF). Among these compounds, the optimally active compound sAc15 elicited a potent protective effect on cell growth of PC12 cells by effectively eliminating ROS generation in response to oxidative stress injury by activating the Nrf2/HO-1 antioxidant signaling pathway. In addition, sAc15 exhibited good protection against CIRI in the mice middle cerebral artery occlusion (MCAO) model. In this paper, we provide a novel class of antioxidants and a potential compound for stroke treatment.
- He, Wenfei,Wang, Jingsong,Jin, Qiling,Zhang, Jiafeng,Liu, Yugang,Jin, Zewu,Wang, Hua,Hu, Linya,Zhu, Lu,Shen, Mengya,Huang, Lili,Huang, Shengwei,Li, Wulan,Zhuge, Qichuan,Wu, Jianzhang
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- Sequential Two-Step Stereoselective Amination of Allylic Alcohols through the Combination of Laccases and Amine Transaminases
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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.
- Albarrán-Velo, Jesús,Lavandera, Iván,Gotor-Fernández, Vicente
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p. 200 - 211
(2019/12/03)
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- One-pot two-step chemoenzymatic deracemization of allylic alcohols using laccases and alcohol dehydrogenases
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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.
- Albarrán-Velo, Jesús,Gotor-Fernández, Vicente,Lavandera, Iván
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- Discovery and Characterization of Pure RhlR Antagonists against Pseudomonas aeruginosa Infections
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Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic human pathogen that forms biofilms and produces virulence factors via quorum sensing (QS). Blocking the QS system in P. aeruginosa is an excellent strategy to reduce biofilm formation and the production of virulence factors. RhlR plays an essential role in the QS system of P. aeruginosa. We synthesized 55 analogues based on the chemical structure of 4-gingerol and evaluated their RhlR inhibitory activities using the cell-based reporter strain assay. Comprehensive structure-activity relationship studies identified the alkynyl ketone 30 as the most potent RhlR antagonist. This compound displayed selective RhlR antagonism over LasR and PqsR, strong inhibition of biofilm formation, and reduced production of virulence factors in P. aeruginosa. Furthermore, the survival rate of Tenebrio molitor larvae treated with 30 in vivo greatly improved. Therefore, compound 30, a pure RhlR antagonist, can be utilized for developing QS-modulating molecules in the control of P. aeruginosa infections.
- Nam, SangJin,Ham, So-Young,Kwon, Hongmok,Kim, Han-Shin,Moon, Suhyun,Lee, Jeong-Hoon,Lim, Taehyeong,Son, Sang-Hyun,Park, Hee-Deung,Byun, Youngjoo
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supporting information
p. 8388 - 8407
(2020/09/21)
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- Iodine/water-mediated deprotective oxidation of allylic ethers to access α,β-unsaturated ketones and aldehydes
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The first iodine/water-mediated deprotective oxidation of allylic ethers to access α,β-unsaturated ketones and aldehydes was achieved. The reaction tolerates a wide range of functionalities. Furthermore, this protocol was found to be applicable to the oxidative transformation of allylic acetates. The proposed mechanism involves an oxygen transfer from solvent water to the carbonyl products.
- Chen, Weifeng,Jiang, Kezhi,Xue, Yuntian,Yan, Yaolong,Yang, Lei
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p. 14720 - 14724
(2020/04/27)
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- Use of a switchable-hydrophilicity solvent as both a solvent and a catalyst in aldol condensation
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A switchable-hydrophilicity solvent, N,N-dimethylcyclohexylamine, was used as a recyclable catalyst and solvent for aldol condensation, giving >97% pure product in 94% isolated yield without the need for purification or additional solvents. CO2-triggered separation produced yields greater than conventional workup and allowed facile recycling of the amine.
- Poole, Hailey,Gauthier, Jeremy,Vanderveen, Jesse R.,Jessop, Philip G.,Lee, Roland
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supporting information
p. 6263 - 6267
(2019/12/03)
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- Enantioselective Copper-Catalyzed 1,5-Cyanotrifluoromethylation of Vinylcyclopropanes
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A copper-catalyzed enantioselective 1,5-cyanotrifluoromethylation of vinylcyclopropanes has been developed using a radical relay strategy. This asymmetric reaction has demonstrated high enantioselective control, broad substrate scope, and mild conditions. Initiated by the in situ generated CF3 radical from Togni's reagent, this method offers a new solution for remote enantioselective bifunctionalization of alkenes and thus provides a straightforward way for the synthesis of chiral CF3-containing internal alkenylnitriles.
- Zhang, Zi-Qi,Meng, Xiang-Yu,Sheng, Jie,Lan, Quan,Wang, Xi-Sheng
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supporting information
p. 8256 - 8260
(2019/10/16)
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- Iron(III)/O2-Mediated Regioselective Oxidative Cleavage of 1-Arylbutadienes to Cinnamaldehydes
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A simple, efficient, and environmentally benevolent regioselective oxidative cleavage of 1-arylbutadienes to cinnamaldehydes mediated by iron(III) sulfate/O2 has been developed. The reaction offered good yields and excellent regioselectivity and showed good functional group tolerance (31 examples). The method is important, as few reports with limited substrate scope are available for such excellent oxidative cleavage of conjugated dienes.
- Bhowmik, Amit,Fernandes, Rodney A.
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supporting information
p. 9203 - 9207
(2019/11/14)
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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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- Rh(III)-Catalyzed Enaminone-Directed Alkenyl C-H Activation for the Synthesis of Salicylaldehydes
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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.
- Qi, Bing,Guo, Shan,Zhang, Wenjing,Yu, Xiaolong,Song, Chao,Zhu, Jin
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supporting information
p. 3996 - 3999
(2018/07/15)
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- Structure-Activity Relationships of 6- and 8-Gingerol Analogs as Anti-Biofilm Agents
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Pseudomonas aeruginosa is a causative agent of chronic infections in immunocompromised patients. Disruption of quorum sensing circuits is an attractive strategy for treating diseases associated with P. aeruginosa infection. In this study, we designed and synthesized a series of gingerol analogs targeting LasR, a master regulator of quorum sensing networks in P. aeruginosa. Structure-activity relationship studies showed that a hydrogen-bonding interaction in the head section, stereochemistry and rotational rigidity in the middle section, and optimal alkyl chain length in the tail section are important factors for the enhancement of LasR-binding affinity and for the inhibition of biofilm formation. The most potent compound 41, an analog of (R)-8-gingerol with restricted rotation, showed stronger LasR-binding affinity and inhibition of biofilm formation than the known LasR antagonist (S)-6-gingerol. This new LasR antagonist can be used as an early lead compound for the development of anti-biofilm agents to treat P. aeruginosa infections.
- Choi, Hyunsuk,Ham, So-Young,Cha, Eunji,Shin, Yujin,Kim, Han-Shin,Bang, Jeong Kyu,Son, Sang-Hyun,Park, Hee-Deung,Byun, Youngjoo
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p. 9821 - 9837
(2017/12/26)
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- Catalytic Asymmetric Conjugate Addition of Indolizines to α,β-Unsaturated Ketones
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A catalytic enantioselective conjugate addition of indolizines to enones is described. The chiral phosphoric acid (S)-TRIP activates α,β-unsaturated ketones, thereby promoting an enantioface-differentiating attack by indolizines. Using this reaction, several alkylated indolizines were synthesized in good yields and with enantiomeric ratios of up to 98:2.
- Correia, José Tiago Menezes,List, Benjamin,Coelho, Fernando
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supporting information
p. 7967 - 7970
(2017/06/27)
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- Discovery of New Monocarbonyl Ligustrazine-Curcumin Hybrids for Intervention of Drug-Sensitive and Drug-Resistant Lung Cancer
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The elevation of oxidative stress preferentially in cancer cells by inhibiting thioredoxin reductase (TrxR) and/or enhancing reactive oxygen species (ROS) production has emerged as an effective strategy for selectively targeting cancer cells. In this study, we designed and synthesized 21 ligustrazine-curcumin hybrids (10a-u). Biological evaluation indicated that the most active compound 10d significantly inhibited the proliferation of drug-sensitive (A549, SPC-A-1, LTEP-G-2) and drug-resistant (A549/DDP) lung cancer cells but had little effect on nontumor lung epithelial-like cells (HBE). Furthermore, 10d suppressed the TrxR/Trx system and promoted intracellular ROS accumulation and cancer cell apoptosis. Additionally, 10d inhibited the NF-κB, AKT, and ERK signaling, P-gp-mediated efflux of rhodamine 123, P-gp ATPase activity, and P-gp expression in A549/DDP cells. Finally, 10d repressed the growth of implanted human drug-resistant lung cancer in mice. Together, 10d acts a novel TrxR inhibitor and may be a promising candidate for intervention of lung cancer.
- Ai, Yong,Zhu, Bin,Ren, Caiping,Kang, Fenghua,Li, Jinlong,Huang, Zhangjian,Lai, Yisheng,Peng, Sixun,Ding, Ke,Tian, Jide,Zhang, Yihua
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p. 1747 - 1760
(2016/03/25)
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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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- 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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- Iridium(I) N-Heterocyclic Carbene (NHC)/Phosphine Catalysts for Mild and Chemoselective Hydrogenation Processes
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The directed chemoselective hydrogenation of olefins has been established by using iridium(I) catalysts, which feature a tuned NHC/phosphine ligand combination. This selective reduction process has been demonstrated in a wide array of solvents, including more environmentally acceptable media, also allowing further refinement of hydrogenation selectivity. The directed, chemoselective hydrogenation of olefins has been established by using iridium(I) catalysts, which feature a tuned NHC/phosphine ligand combination. This selective reduction process has been demonstrated in a wide array of solvents, including more environmentally acceptable media, also allowing further refinement of hydrogenation selectivity.
- Kerr, William J.,Mudd, Richard J.,Brown, Jack A.
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supporting information
p. 4738 - 4742
(2016/04/05)
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- Synthesis, cytotoxicity against human oral cancer KB cells and structure-activity relationship studies of trienone analogues of curcuminoids
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A general method for the synthesis of substituted (1E,4E,6E)-1,7- diphenylhepta-1,4,6-trien-3-ones, based on the aldol condensations of substituted 4-phenylbut-3-en-2-ones and substituted 3-phenylacrylaldehydes, was achieved. The natural trienones 4 and 5 have been synthesized by this method, together with the trienone analogues 9-20. These analogues were evaluated for their cytotoxic activity against human oral cancer KB cell line. The structure-activity relationship study has indicated that the analogues with the 1,4,6-trien-3-one function are more potent than the curcuminoid-type function. Analogues with meta-oxygen function on the aromatic rings are more potent than those in the ortho- and para-positions. Free phenolic hydroxy group is more potent than the corresponding methyl ether analogues. Among the potent trienones, compounds 11, 18 and 20 were more active than the anticancer drug ellipticine. All compounds were also evaluated against the non-cancerous Vero cells and it was found that compounds 11, 12 and 17 were much less toxic than curcumin (1); they showed high selectivity indices of 35.46, 33.46 and 31.68, respectively. These analogues are regarded as the potent trienones for anti-oral cancer study.
- Chuprajob, Thipphawan,Changtam, Chatchawan,Chokchaisiri, Ratchanaporn,Chunglok, Warangkana,Sornkaew, Nilubon,Suksamrarn, Apichart
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supporting information
p. 2839 - 2844
(2014/06/10)
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- Novel colchicine-site binders with a cyclohexanedione scaffold identified through a ligand-based virtual screening approach
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Vascular disrupting agents (VDAs) constitute an innovative anticancer therapy that targets the tumor endothelium, leading to tumor necrosis. Our approach for the identification of new VDAs has relied on a ligand 3-D shape similarity virtual screening (VS) approach using the ROCS program as the VS tool and as query colchicine and TN-16, which both bind the α,β-tubulin dimer. One of the hits identified, using TN-16 as query, has been explored by the synthesis of its structural analogues, leading to 2-(1-((2-methoxyphenyl) amino)ethylidene)-5-phenylcyclohexane-1,3-dione (compound 16c) with an IC 50 = 0.09 ± 0.01 μM in HMEC-1 and BAEC, being 100-fold more potent than the initial hit. Compound 16c caused cell cycle arrest in the G2/M phase and interacted with the colchicine-binding site in tubulin, as confirmed by a competition assay with N,N′-ethylenebis(iodoacetamide) and by fluorescence spectroscopy. Moreover, 16c destroyed an established endothelial tubular network at 1 μM and inhibited the migration and invasion of human breast carcinoma cells at 0.4 μM. In conclusion, our approach has led to a new chemotype of promising antiproliferative compounds with antimitotic and potential VDA properties.
- Canela, María-Dolores,Pérez-Pérez, María-Jesús,Noppen, Sam,Sáez-Calvo, Gonzalo,Díaz, J. Fernando,Camarasa, María-José,Liekens, Sandra,Priego, Eva-María
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supporting information
p. 3924 - 3938
(2014/06/09)
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- Iridium(I)-catalyzed regioselective C-H activation and hydrogen-isotope exchange of non-aromatic unsaturated functionality
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Isotopic labelling is a key technology of increasing importance for the investigation of new C-H activation and functionalization techniques, as well as in the construction of labelled molecules for use within both organic synthesis and drug discovery. Herein, we report for the first time selective iridium-catalyzed C-H activation and hydrogen-isotope exchange at the β-position of unsaturated organic compounds. The use of our highly active [Ir(cod)(IMes)(PPh3)][PF6] (cod = 1, 5-cyclooctadiene) catalyst, under mild reaction conditions, allows the regioselective β-activation and labelling of a range of α, β-unsaturated compounds with differing steric and electronic properties. This new process delivers high levels of isotope incorporation over short reaction times by using low levels of catalyst loading.
- Kerr, William J.,Mudd, Richard J.,Paterson, Laura C.,Brown, Jack A.
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supporting information
p. 14604 - 14607
(2015/03/04)
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- Wacker-type oxidation and dehydrogenation of terminal olefins using molecular oxygen as the sole oxidant without adding ligand
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An efficient and economical palladium-catalyzed oxidation system has been identified. The oxidation system, characterized by not adding ligand and using molecular oxygen as the sole oxidant, can realize the Tsuji-Wacker oxidation of terminal olefins and especially styrenes to methyl ketones; in addition, this system can achieve tandem Wacker oxidation-dehydrogenation of terminal olefins to α,β-unsaturated ketones.
- Wang, Yu-Fei,Gao, Ya-Ru,Mao, Shuai,Zhang, Yan-Lei,Guo, Dong-Dong,Yan, Zhao-Lei,Guo, Shi-Huan,Wang, Yong-Qiang
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supporting information
p. 1610 - 1613
(2014/04/17)
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- Enantioselective [4 + 2] cycloaddition of cyclic N-sulfimines and acyclic enones or ynones: A concise route to sulfamidate-fused 2,6-disubstituted piperidin-4-ones
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A concise route to valuable sulfamate-fused 2,6-disubstituted piperidin-4-ones or 2,3-dihydropyridin-4(1H)-ones in good yield with high diastereo- and enantioselectivity is presented. The combination of chiral primary amine and o-fluorobenzoic acid efficiently promoted an asymmetric [4 + 2] cycloaddition reaction of N-sulfonylimines and enones or ynones. The cycloaddition reaction between cyclic N-sulfonylimines and ynones is first reported.
- Liu, Yong,Kang, Tai-Ran,Liu, Quan-Zhong,Chen, Lian-Mei,Wang, Ya-Chuan,Liu, Jie,Xie, Yong-Mei,Yang, Jin-Liang,He, Long
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p. 6090 - 6093
(2014/01/06)
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- Highly enantioselective biomimetic intramolecular dehydration: Kinetic resolution of β-hydroxy ketones catalyzed by β-turn tetrapeptides
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Racemic β-hydroxy ketones were kinetically resoluted into the enantiopure isomers and (E)-α,β-unsaturated ketones using catalytic asymmetric intramolecular dehydration for the first time. Synthetic tetrapeptides were used to imitate fatty acid dehydratase
- Du, Zhi-Xue,Zhang, Li-Yuan,Fan, Xin-Yuan,Wu, Feng-Chun,Da, Chao-Shan
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supporting information
p. 2828 - 2832
(2013/06/05)
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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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- First bovine serum albumin-promoted synthesis of enones, cinnamic acids and coumarins in ionic liquid: An insight into the role of protein impurities in porcine pancreas lipase for olefinic bond formation
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During studies on exploiting the catalytic promiscuity of crude porcine pancreas lipase (PPL) in ionic liquid for C=C bond formations, bovine serum albumin (BSA) was found to be competing for these reactions. After a detailed investigation, we establish that these transformations are possible by unspecific protein catalysis rather than catalytic promiscuity of "PPL" - a first insight into the role of protein impurities in crude enzyme. Thus, a novel and highly efficient, environmentally friendly approach involving synergistic catalysis by bovine serum albumin-1-butyl-3- methylimidazolium bromide (BSA-[bmim]Br) has been developed for the synthesis of (E)-α,β-unsaturated compounds including a one-pot cascade synthesis of cinnamic acids and coumarins via aldol, Knoevenagel and Knoevenagel-Doebner condensations.
- Sharma, Nandini,Sharma, Upendra K.,Kumar, Rajesh,Katoch, Nidhi,Kumar, Rakesh,Sinha, Arun K.
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experimental part
p. 871 - 878
(2011/06/19)
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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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- Asymmetric crossed-conjugate addition of nitroalkenes to enones by a chiral bifunctional diamine organocatalyst
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The crossed-conjugate addition involving the electronwithdrawing group (EWG) of activated alkenes is considered one of the most important C-C bond-forming reactions in organic synthesis. Among them, the β,β-disubstituted nitroolefins as powerful synthons have attracted considerable attention recently because the functionalized products can undergo transformations into useful skeletons. Asymmetric intermolecular crossed-conjugate addition between β-alkyl nitroalkenes and a,b-unsaturated carbonyl compounds to provide allylic nitro compounds with multiple stereogenic centers is still rare. The key challenges are to avoid the homo-crossed addition and realize perfect stereochemical control. Shi and co-workers developed the first asymmetric crossed-conjugate addition of β-alkyl nitroalkenes and enals catalyzed by a chiral diphenylprolinol though a dual activation strategy using a stoichiometric amount of (MeO)3P as a Lewis base (LB) (Scheme 1, path A). Although the secondary amines proved to be effective catalysts in the crossed-Michael addition of nitro activated olefins to carbonyl compounds through the LB nucleophilic mechanism, the enantioselective process awaits further investigation.We envisioned that a chiral diamine catalyst would promote the enantioselective crossed-conjugate addition by a bifunctional activation approach (Scheme 1, path B). Herein, we report the chiral primary-secondary diamine Bronsted acid catalyzed asymmetric crossed-conjugate addition of β-methyl nitroalkenes with α, β-unsaturated acyclic and cyclic ketones with excellent enantioselectivities under mild conditions.
- Wang, Min,Lin, Lili,Shi, Jian,Liu, Xiaohua,Kuang, Yulong,Feng, Xiaoming
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supporting information; experimental part
p. 2365 - 2368
(2011/04/16)
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- A selective and benign synthesis of functionalized benzalacetones via Mizoroki-Heck reaction using aryldiazonium salts
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Palladium-catalyzed Mizoroki-Heck reactions were carried out in the presence of calcium carbonate in alcoholic solvents. Under these conditions an efficient preparation of functionalized benzalacetones was developed. The reactions were carried out at room temperature and aerobic conditions, giving the products within several minutes in up to 95% isolated yields. Furthermore, some kinetic investigations, mechanistic insights and considerations are presented.
- Stern, Therese,Rueckbrod, Sven,Czekelius, Constantin,Donner, Constanze,Brunner, Heiko
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experimental part
p. 1983 - 1992
(2010/11/04)
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- Enantioselective α-arylation of aldehydes via organo-SOMO catalysis. An ortho-selective arylation reaction based on an open-shell pathway
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(Chemical Equation Presented) The intramolecular-arylation of aldehydes has been accomplished using singly occupied molecular orbital (SOMO) catalysis. Selective oxidation of chiral enamines (formed by the condensation of an aldehyde and a secondary amine catalyst) leads to the formation of a 3π-electron radical species. These chiral SOMO-activated radical cations undergo enantioselective reaction with an array of pendent electron-rich aromatics and heterocycles thus efficiently providing cyclic α-aryl aldehyde products (10 examples: ≥70% yield and ≥90% ee). In accordance with our radical mechanism, when there is a choice between arylation at the ortho or para position of anisole substrates, we find that arylation proceeds selectively at the ortho position.
- Conrad, Jay C.,Kong, Jongrock,Laforteza, Brian N.,MacMillan, David W. C.
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supporting information; experimental part
p. 11640 - 11641
(2009/12/08)
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- Lipase-catalysed decarboxylative aldol reaction and decarboxylative Knoevenagel reaction
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Acrylic resin immobilized Candida antarctica lipase B (CAL-B) is able to catalyse decarboxylative aldol reaction and decarboxylative Knoevenagel reaction with good to excellent yields.
- Feng, Xing-Wen,Li, Chao,Wang, Na,Li, Kun,Zhang, Wei-Wei,Wang, Zao,Yu, Xiao-Qi
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scheme or table
p. 1933 - 1936
(2010/06/15)
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- NOVEL THIENOPYRIMIDINE DERIVATIVES OR PHARMACEUTICALLY ACCEPTABLE SALTS THEREOF, PROCESS FOR THE PREPARATION THEREOF AND PHARMACEUTICAL COMPOSITION COMPRISING THE SAME
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The present invention relates to a novel thienopyrimidine derivative having an excellent anti? inflammatory and anti-cancer activity, or a pharmaceutically acceptable salt thereof, a process for the preparation thereof and a pharmaceutical composition comprising the same. The compound according to the present invention strongly inhibits IKB kinase-β (IKK-β) involved in the activation of a transcriptional factor, NF-κB, which is associated with inducing various immune and inflammatory diseases, whereby a composition comprising the compound is a useful therapeutic agent against inflammatory diseases, in particular, arthritis and cancer.
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Page/Page column 86-87
(2010/11/28)
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- Synthesis of Quinolines and 2H-Dihydropyrroles by Nucleophilic Substitution at the Nitrogen Atom of Oxime Derivatives
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Isomerization of oxime derivatives was researched in detail to find out the methods for the syn-anti isomerization of O-substituted oximes. Based on these findings were developed simple methods for the preparation of aza-heterocycles from both stereoisomers of oximes. Quinolines were synthesized from β-aryl ketone oximes by treatment with trifluoroacetic anhydride and 4-chloranil. γ,δ-Unsaturated O-methoxyacetyloximes were transformed to 2H-dihydropyrroles by reaction with methoxy-acetic acid.
- Kitamura, Mitsuru,Yoshida, Masayuki,Kikuchi, Takashi,Narasaka, Koichi
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p. 2415 - 2426
(2007/10/03)
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- Transformation of oximes of phenetyl ketone derivatives to quinolines and azaspirotrienones catalyzed by tetrabutylammonium perrhenate and trifluoromethanesulfonic acid
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Phenethyl ketone oximes are converted to quinolines by the treatment with tetrabutylammonium perrhenate, trifluoromethanesulfonic acid, and chloranil in refluxing 1,2-dichloroethane. Azaspirotrienones can be synthesized from p-hydroxyphenethyl or 3-(p-hydroxyphenyl)propyl ketone oximes by applying the above method. Thus prepared azaspirotrienones are converted to quinolines by acid treatment.
- Kusama,Yamashita,Uchiyama,Narasaka
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p. 965 - 975
(2007/10/03)
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- Palladium-catalyzed aldol-type condensation by enol esters with SnCl2
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Using PdCl2(PhCN)2-SnCl2, enol esters caused aldol-type condensation with aldehydes at 50°C in acetonitrile to produce (E)-α,β-unsaturated carbonyl compounds. Cyclic enol ester such as α-angelicalactone also reacted with aldehydes under the same conditions to afford γ-substituted β-acetyle-γ-butyrolactones and/or 5-substituted 4-acetyl-2(5H)-furanones.
- Masuyama, Yoshiro,Sakai, Tatsuya,Kurusu, Yasuhiko
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p. 653 - 656
(2007/10/02)
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- Synthesis of 1,3-Diol Synthons from Epoxy Aromatic Precursors: An Approach to the Construction of Polyacetate-Derived Natural Products
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The identification of stereoregular polyol subunits within polyacetate-derived natural products such as bryostatin 1 and amphotericin B has led to the convergent synthesis of six- and seven-carbon 1,3-diol fragments in high yields and stereoselectivities.This plan relies upon the enantioselective asymmetric epoxidation/kinetic resolution of cinnamyl alcohols and the use of meta-substituted anisyl rings as masked β-keto ester synthons.Birch reduction of 9 (R = SiiPr3) followed by ozonolysis afforded the hydroxyl keto ester 11 in 66percent overall yield.Anti-selective β-selective β-hydroxy ketone reduction employing Me4NBH(OAc)3 afforded 12 in 93percent yield and 13:1 diastereoselectivity while syn-selective reduction with Et2BOMe/NaBH4 gave 13 in 82percent yield and 15:1 diastereoselectivity.An analogous sequence of reactions provided 25 and 26 from epoxy alcohol 18.Epoxy aromatic alcohol 17 (R = H) was easily converted to 18 (93percent yield, > 99:1) by Mitsunobu inversion followed by methanolysis.This reaction sequence provides access to all stereoisomers of 3,5,6-trihydroxyhexanoic acid heptanoic acids which should be useful chiral subunits of polyacetate-derived natural products such as amphotericin and bryostatin.
- Evans, David A.,Gauchet-Prunet, Joelle A.,Carreira, Erick M.,Charette, Andre B.
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p. 741 - 750
(2007/10/02)
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- Methods for the treatment of hypertension
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Acetylene compounds of the formula (I): STR1 wherein Y, R1, R2, R3, and R4 are as described herein, m is 0-3, n is 0-2 and Ar is phenyl or an aromatic heterocycle are disclosed. The compounds possess antihyperte
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- Acetylene amines and their use as vasodilators and antihypertensives
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Acetylenes of the following formula (I): STR1 wherein Y, m, R1, R2, R3, n and R4 are defined herein and R5 is hydrogen, alkyl, cycloalkyl or substituted alkyl are useful vasodilators and antihypertens
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- Aralykyl (arylethynyl)aralkyl amines and their use as vasodilators and antihypertensives
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Acetylenes of the formula (I): STR1 wherein Y, m, R1, R2 q, Alk, R3, n and R4 are as defined herein and Ar1 and Ar2 are aromatic, including the salts and ammonium derivatives of formula (I), in treating angina, hypertension and cardiac arrhythmias. Pharmaceutical compositions, methods of use and synthesis and novel intermediates are also part of the invention.
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- Mannich Bases of 4-Phenyl-3-buten-2-one: A New Class of Antiherpes Agent
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The morpholine Mannich base of 4-phenyl-3-buten-2-one was found to have activity in model infections of herpes simplex.The activity was essentially equivalent to that of disodium phosphonoacetate.This paper presents the biological activity and synthesis o
- Edwards, M.L.,Ritter, H.W.,Stemerick, D.M.,Stewart, K.T.
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p. 431 - 436
(2007/10/02)
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