- Metal- and Solvent-Free Transesterification and Aldol Condensation Reactions by a Homogenous Recyclable Basic Ionic Liquid Based on the 1,3,5-Triazine Framework
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A new recyclable basic ionic liquid was introduced as an efficient catalyst for aldol condensation and transesterification reactions under environmentally friendly conditions. The catalyst was prepared based on methyl imidazolium moieties bearing hydroxide counter anions via the Hofmann elimination on a 1,3,5-triazine framework. The ionic liquid with two functionalities including anion stabilizer and high basicity, was used as an efficient catalyst for aldol condensation as well as transesterification reaction of a variety of alkyl benzoates. All reactions were performed in the absence of any external reagent, co-catalyst, or solvent, in line with environmental protection. The kinetics isotope effect (KIE) was conducted for the transesterification reaction to elucidate the mechanism and rate determining step (RDS). It worth noted that, the homogeneous catalyst could be recycled from the reaction mixture and reused for several consecutive runs with insignificant drop of basicity and conversion.
- Hu, Yanqiu,Kazemnejadi, Milad,Ren, Mingqi
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p. 775 - 783
(2021/08/30)
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- RhIII-Catalyzed Synthesis of Highly Substituted 2-Pyridones using Fluorinated Diazomalonate
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A RhIII-catalyzed strategy was developed for the rapid construction of highly substituted 2-pyridone scaffolds using α,β-unsaturated oximes and fluorinated diazomalonate. The reaction proceeds through direct, site-selective alkylation based on migratory insertion and subsequent cyclocondensation. A wide substrate scope with different functional groups was explored. The requirement of fluorinated diazomalonate was explored for this transformation. The developed methodology was further extended with the synthesis of the bioactive compound.
- Das, Debapratim,Sahoo, Gopal,Biswas, Aniruddha,Samanta, Rajarshi
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supporting information
p. 360 - 364
(2020/01/25)
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- Synthesis and biological evaluation of novel active arylidene derivatives of 5,6-dihydro-4H-cyclopenta[b]- and 4,5,6,7-tetrahydrobenzo[b]-thiophene-2-carboxylic acid
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A series of novel arylidene derivatives of 5,6-dihydro-4H-cyclopenta[b]-thiophene-2-carboxylic acid and 4,5,6,7-tetrahydrobenzo[b]-thiophene-2-carboxylic acid were synthesized by reacting benzylidene derivatives of chloro aldehyde with 2-mercaptoacetic acid. Benzylidene derivatives of chloro aldehyde were prepared from Vilsmeier reaction of 2-benzylidenecyclopentanone and 2-benzylidenecyclohexanone derivatives, obtained from condensation of various aromatic aldehydes with cyclopentanone and cyclohexanone. All synthesized compounds were characterized by nuclear magnetic resonance (NMR), infrared (IR), and mass spectroscopy and X-ray single-crystal analysis. The synthesized compounds were screened for their in?vitro antimicrobial and antifungal activity. Good antimicrobial activity, especially against methicillin-resistant Staphylococcus aureus, was observed for most of the compounds tested. In particular, compound 9f emerged as an effective antibacterial agent and may be a potential candidate for future drug discovery and development.
- Kathiravan,Venugopal,Muthukumaran
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p. 2315 - 2331
(2017/03/22)
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- Ultrasound mediation for efficient synthesis of monoarylidene derivatives of homo- and heterocyclic ketones
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Ultrasonic irradiation was efficiently used for high yield synthesis of monoarylidene derivatives of cyclic systems directly from the reaction of ketone with various aldehydes under solvent-free conditions. Reactions took place rapidly in the presence of catalytic amounts of pyrrolidine, while no significant formation of the undesired bis by-products was observed. Moreover, the procedure was applicable to both homo- and heterocyclic ketones.
- Mojtahedi, Mohammad M.,Abaee, M. Saeed,Samianifard, Mehdieh,Shamloo, Akram,Padyab, Masoomeh,Mesbah, A. Wahid,Harms, Klaus
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p. 924 - 930
(2013/03/13)
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- 2-METHYLENE-5-SUBSTITUTED-METHYLENECYCLOPENTANONE DERIVATIVES AND USE THEREOF
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The invention relates to 2-methylene-5-substituted-methylenecyclopentanone derivatives of formula I, and the use thereof. The derivatives of formula I as active components are useful for preparing a medicine for the treatment and/or prevention of cancer diseases such as breast cancer, lung cancer, colon cancer, rectal cancer, stomach cancer, prostate cancer, bladder cancer, uterus cancer, pancreatic cancer and ovary cancer. The active compounds of the invention may be used as an anticancer drug alone or used in combination with one or more other antitumor drugs. A combined therapy can be carried out by administrating each therapeutic component concurrently, subsequently or separately.
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Page/Page column 4
(2011/04/18)
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- An efficient procedure for the synthesis of α,β-unsaturated ketones and its application to heterocyclic systems
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An efficient and room-temperature procedure is developed for high yield synthesis of novel α,β-unsaturated derivatives of thiopyran 3 directly from ketone 1 and various aldehydes in the presence of catalytic quantities of TMSNMe2 and MgBr2OEt2 under solvent-free conditions. The main advantage of the procedure is that the formation of the undesired bis by-products is minimized. In addition, the procedure is applicable to other enolizable carbocyclic and acyclic ketones. Georg Thieme Verlag Stuttgart. New York.
- Mojtahedi, Mohammad M.,Abaee, M. Saeed,Khakbaz, Mehdi,Alishiri, Tooba,Samianifard, Maedeh,Mesbah, A. Wahid,Harms, Klaus
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experimental part
p. 3821 - 3826
(2012/01/06)
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- Facile synthesis and characterization of substituted pyrimidin-2(1H)-ones and their chalcone precursors
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A new and efficient method has been developed for the quantitative transformation of chalcones to pyrimidine frame work vSa solid support catalysis, Silica supported sulphuric acid (SSA) efficiently catalyzed the reaction of α-β-unsaturated earbonyl, chalcones (140) with urea to afford substituted pyriniidin-2(1H)-ones (11-20) hi good to excellent yield. The interesting behaviour of SSA lies in the thct that it can be re-used after simple washing with chloroform thereby rendering this procedure more economical, The chemical structures were confirmed by analytical data as well as spectroscopic means.
- Ajani, Olayinka Oyewale,Ituen, Ruth Itoroabasi,Falomo, Ayorinde
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experimental part
p. 59 - 67
(2012/06/01)
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- 2-METHYLENE-5-SUBSTITUTED METHYLENE CYCLOPENTANONE DERIVATIVES AND USE THEREOF
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The invention relates to 2-methylene-5-substituted-methylenecyclopentanone derivatives of formula I, and the use thereof. The derivatives of formula I as active components are useful for preparing a medicine for the treatment and/or prevention of cancer diseases such as breast cancer, lung cancer, colon cancer, rectal cancer, stomach cancer, prostate cancer, bladder cancer, uterus cancer, pancreatic cancer and ovary cancer. The active compounds of the invention may be used as an anticancer drug alone or used in combination with one or more other antitumor drugs. A combined therapy can be carried out by administrating each therapeutic component concurrently, subsequently or separately.
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Page/Page column 6
(2010/11/19)
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- Carbamoyloximes as novel non-competitive mGlu5 receptor antagonists
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Hit-to-lead optimization of a HTS hit led to new carbamoyloxime derivatives. After identification of an advanced hit (8d) the CYP enzyme inhibitory activity of this class of compounds was successfully eliminated. Systematic exploration of different parts of the advanced hit led us to some promising lead compounds with mGluR5 affinities comparable to that of MPEP.
- Galambos, Janos,Wagner, Gabor,Nogradi, Katalin,Bielik, Attila,Molnar, Laszlo,Bobok, Amrita,Horvath, Attila,Kiss, Bela,Kolok, Sandor,Nagy, Jozsef,Kurko, Dalma,Bakk, Monika L.,Vastag, Monika,Saghy, Katalin,Gyertyan, Istvan,Gal, Krisztina,Greiner, Istvan,Szombathelyi, Zsolt,Keser, Gyoergy M.,Domany, Gyoergy
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scheme or table
p. 4371 - 4375
(2010/10/02)
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- Conjugate addition of allyl stannanes with concomitant triflation
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A new method for the conjugate addition of allyltributylstannane with concomitant triflation is described. This reaction works with functionalized enones, enals, enoates, and vinylogous esters. The resulting vinyl triflates can be used for intramolecular Heck reactions to afford the products of 5-exo-trig cyclization.
- Beaulieu, Ellen D.,Voss, Leah,Trauner, Dirk
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supporting information; experimental part
p. 869 - 872
(2009/04/07)
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- Quinoline synthesis: Scope and regiochemistry of photocyclisation of substituted benzylidenecyclopentanone O-alkyl and O-acetyloximes
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Irradiation of substituted 2-benzylidenecyclopentanone O-alkyl and O-acetyloximes in methanol provides a convenient synthesis of alkyl, alkoxy, hydroxy, acetoxy, amino, dimethylamino and benzo substituted annulated quinolines. para-Substituents yield 6-substituted-2,3-dihydro-1H-cyclopenta[b] quinolines with 8-substituted products being obtained from ortho-substituted starting materials. Reactions of meta-substituted precursors are highly regioselective, with alkyl substituents leading to 5-substituted 2,3-dihydro-1H-cyclopenta[b]quinolines and more strongly electron-donating substituents generally resulting in 7-substituted products. 2-Furylmethylene and 2-thienylmethylene analogues yield annulated furo- and thieno-[2,3e]pyridines respectively. Sequential E- to Z-benzylidene group isomerisation and six π-electron cyclisation steps result in formation of a short-lived dihydroquinoline intermediate which spontaneously aromatises by elimination of an alcohol or acetic acid. For 2-benzylidenecyclopentanone O-allyloxime, singlet excited states are involved in both steps. The Royal Society of Chemistry 2007.
- Austin, Mark,Egan, Oliver J.,Tully, Raymond,Pratt, Albert C.
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p. 3778 - 3786
(2008/10/09)
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- A new protocol for synthesis of α,β-unsaturated ketones using zirconium tetrachloride under microwave irradiation
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A facile one-pot synthesis of α,β-unsaturated carbonyl compound has been accomplished from ZrCl4 mediated condensation of α-bromo ketones with aryl aldehydes under microwave irradiation.
- Bora, Utpal,Saikia, Anil,Boruah, Romesh C.
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p. 2523 - 2526
(2007/10/03)
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- Reactions of tin(IV) enolates obtained from O-stannyl ketyls under neutral free radical conditions
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Under mild and neutral free radical conditions, an α,β-unsaturated ketone reacted with tributyltin hydride to produce an intermediate resonance-stabilized allylic O-stannyl ketyl. Upon subsequent hydrogen atom abstraction, a tin(IV) enolate was afforded which could be quenched with a variety of electrophiles and form new carbon-carbon bonds. Aldehydes react to produce aldol-type products and both intramolecular and intermolecular carbonyl addition reactions were investigated using this strategy. Using similar methodology, the tin(IV) enolate could be quenched in the presence of HMPA with various alkyl halides and α,β-unsaturated carbonyl compounds (Michael acceptors) to yield alkylated products in good yields. These reactions represent a very mild regioselective alternative to metal enolate formation which usually requires strong bases such as LDA or strongly reductive dissolving metal conditions to achieve success. New carbon skeletons for natural product synthesis can be readily constructed using this chemically neutral approach.
- Enholm, Eric J.,Whitley, Paul E.,Xie, Yongping
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p. 5384 - 5390
(2007/10/03)
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- INTERMOLECULAR ALDOL REACTIONS VIA ALLYLIC O-STANNYL KETYLS
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A mild and neutral free radical reaction of an α,β-unsaturated ketone and tributyltin radical produced a resonance-stabilized allylic O-stannyl ketyl intermediate.A tin(IV)enolate, produced by subsequent hydrogen atom transver, was next quenched with various aldehydes to yield an aldol product which was readily eliminated with p-toluenesulfonic acid to afford new α,β-unsaturated ketones with E/Z ratios up to > 100:1.
- Enholm, Eric J.,Whitley, Paul E.
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p. 9157 - 9160
(2007/10/02)
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- Free-radical-mediated Carbonylative Cyclization of Alk-4-enyl Halides Leading to Cyclopentanone
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Alk-4-enyl bromides and iodides 1, when treated with the tributyltin hydride/CO sustem, undergo carbonylative cyclization to give cyclopentanones in good yields (AIBN cat., benzene, 79-90 atm, = 0.025-0.05 mol dm-3, 80 deg C.
- Ryu, Ilhyong,Kusano, Kazuya,Hasegawa, Mitsuharu,Kambe, Nobuaki,Sonoda, Noboru
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p. 1018 - 1019
(2007/10/02)
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- ALDOL CONDENSATIONS WITH METAL(II) COMPLEX CATALYSTS.
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Aldol condensations of aldehydes with ketones catalyzed by the first-row transition metal(II) complexes have been widely studied. Complexes of Co(II), Ni(II), Cu(II), and Zn(II) acetates with 2,2 prime -bypyridine were effective catalysts to afford cross-aldol condensation products, alpha , beta ,-unsaturated ketones, in high yields without any self-condensation products. The reaction of 2-butanone, unsymmetrical aliphatic ketone, with benzaldehyde took place regioselectively to give base-catalyzed-type products.
- Irie,Watanabe
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p. 1366 - 1371
(2007/10/02)
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