2601-03-8Relevant articles and documents
Hypervalent Iodine(III)-Catalyzed Epoxidation of β-Cyanostyrenes
Mangaonkar, Saeesh R.,Singh, Fateh V.
, p. 4473 - 4486 (2019/11/21)
A convenient approach for the synthesis of β-cyanoepoxides is illustrated by iodine(III)-catalyzed epoxidation of electron-deficient β-cyanostyrenes, wherein the active catalytic iodine(III) species was generated in situ. The epoxidation of β-cyanostyrenes was performed using 10 molpercent PhI as precatalyst in the presence of 2.0 equivalents Oxone as an oxidant and 2.4 equivalents of TFA as an additive at room temperature under ultrasonic radiations. The β-cyanoepoxides were isolated in good to excellent yields in a short reaction time.
The Knoevenagel condensation using quinine as an organocatalyst under solvent-free conditions
Jain, Kavita,Chaudhuri, Saikat,Pal, Kuntal,Das, Kalpataru
supporting information, p. 1299 - 1304 (2019/01/21)
The Knoevenagel condensation between active methylene compounds and aromatic carobonyl compounds has been developed using quinine as an organocatalyst to afford various electrophilic alkenes in excellent yields (up to 90%). In the presence of a catalytic amount of quinine (15 mol%), the reaction proceeded at room temperature (RT) under solvent-free conditions. In this green approach, the organocatalyst was recovered and recycled for up to four cycles without appreciable loss of activity.
A functionalized UiO-66 MOF for turn-on fluorescence sensing of superoxide in water and efficient catalysis for Knoevenagel condensation
Das, Aniruddha,Anbu, Nagaraj,Sk, Mostakim,Dhakshinamoorthy, Amarajothi,Biswas, Shyam
, p. 17371 - 17380 (2019/12/02)
In the present work, a new MOF material of the UiO-family called Zr-UiO-66-NH-CH2-Py (1) has been obtained by the solvothermal technique and successfully characterized. The MOF structure was assembled with 2-((pyridin-4-ylmethyl) amino) terephthalic acid (H2BDC-NH-CH2-Py) as linker and Zr4+ ion. The activated form of 1 (called 1′) exhibits considerable thermal and chemical stability. Compound 1′ showed a very rapid and selective response for the fluorometric sensing of superoxide (O2·-) in aqueous medium even in the presence of the potentially competitive reactive oxygen species (ROS). The limit of detection value for O2·- sensing is 0.21 μM, which is comparable with those of the reported O2·- sensors. This is the first MOF based fluorescent sensor for the detection of O2·-. The response time of this MOF sensor for O2·- is very short (240 s). On the other hand, 1′ was employed as a solid heterogeneous catalyst for Knoevenagel condensation between benzaldehyde and ethyl cyanoacetate at 80 °C in ethanol resulting in a very high yield of the desired product. The effects of the esterified linker ((CH3)2BDC-NH-CH2-Py) and the corresponding metal salt (ZrCl4) on this catalytic reaction were examined separately. We have also tested the substrate scope elaborately for the catalytic reaction promoted by catalyst 1′.
Microwave assisted urea-acetic acid catalyzed knoevenagel condensation of ethyl cyanoacetate and 1,3-Thiazolidine-2,4-dione with aromatic aldehydes under solvent free condition
Tryambake, Pravin. T.
, p. 2401 - 2405 (2017/10/31)
Knoevengel condensation reaction of various aromatic aldehydes with ethyl cyanoacetate and 1,3-thiazolidinone-2,4-diones catalyzed by urea-acetic acid under solvent free condition where olefinic products were obtained in high yield within short reaction time.
Straightforward syntheses of nitriles, acrylates, and acrylamides in aqueous propan-1,2-diol: A catalyst free and waste free methodology
Jayalakshmi, Lakshmi Narayanan,Karuppasamy, Ayyanar,Stalindurai, Kesavan,Sivaramakarthikeyan, Ramar,Devadoss, Vellasamy,Ramalingan, Chennan
supporting information, p. 4207 - 4210 (2015/06/22)
A mild, elegant, catalyst free, and waste free methodology has been developed for the clear-cut synthesis of a diverse range of nitriles, acrylates, and acrylamides in good to excellent yields using aqueous propan-1,2-diol, a green reaction medium, at ambient temperature. Operational simplicity and recyclability of the reaction medium are added advantages of the methodology.
One-by-one hydrogenation, cross-coupling reaction, and Knoevenagel condensations catalyzed by PdCl2 and the downstream palladium residue
Wang, Hu,Li, Li,Bai, Xing-Feng,Deng, Wen-Hui,Zheng, Zhan-Jiang,Yang, Ke-Fang,Xu, Li-Wen
supporting information, p. 2349 - 2355 (2013/09/12)
A novel catalyst-economic strategy with a recovered palladium catalyst was successfully applied for multi-task and maximum reuse in different types of one-by-one downstream reactions, from catalytic hydrogenation to Suzuki and Sonogashira-type cross-coupling reactions, Knoevenagel condensations, and trans-Knoevenagel-like condensations.
A highly efficient protocol for the regio- and stereo-selective synthesis of spiro pyrrolidine and pyrrolizidine derivatives by multicomponent reaction
Dandia, Anshu,Jain, Anuj K.,Laxkar, Ashok K.,Bhati, Dharmendra S.
, p. 3180 - 3184 (2013/06/27)
A series of novel spiro[acenaphthylene-1,2′-pyrrolidine] (4), spiro[acenaphthylene-1,2′-pyrrolizidine] (7), and spiro[indoline-3, 2′-pyrrolidine] derivatives (9) containing cyano group were successfully synthesized via a three-component 1,3-dipolar cycloaddition reaction of acenaphthenequinone or isatin, sarcosine or proline, and Knoevenagel adducts in refluxing aqueous methanol. In this intermolecular three-component combinatorial process it is amazing that three stereogenic centers with one spiro carbon are controlled very well. The structure and relative stereo-chemistry of cycloadducts were carried out by single crystal X-ray diffraction, as well as by the help of 1H, 13C, and HMBC spectroscopy.
A systematic study on Knoevenagel reaction and Nazarov cyclization of less reactive carbonyl compounds using rare earth triflates and its applications
Ilangovan,Muralidharan,Maruthamuthu
experimental part, p. 1000 - 1006 (2012/02/05)
A systematic study of Knoevenagel reaction and Nazarov cyclization was made on variety of less reactive carbonyl compounds such as β-ketoesters, 1,3-diketones and cyclic active methylene compounds using Yb(OTf)3 as the catalyst. Recycling study confirms reusability of the catalyst without much loss of activity.
Synthesis and biological evaluation of 3-amino pyrazolones
Rajitha, Galla,Prasad,Bharathi, Koganti
experimental part, p. 684 - 686 (2011/12/22)
A series of 3-amino-4-(substituted benzylidene)-1H-pyrazol-5(4H)-ones were synthesized by condensation of ethyl-2-cyano-3-(substituted) phenylacrylates with hydrazine hydrate. The chemical structures of synthesized compounds were confirmed by means of IR,
Reaction of ethyl cyanoacetate with benzal-4-acetylanilines: An unexpected result
Sidhu, Anjali,Rai, Mangat
, p. 778 - 780 (2008/12/20)
Reaction of ethyl cyanoacetate with benzal-4-acetylanilines 1a-10a, the compounds containing both azomethine and ketone linkages, in equimolar ratio, in the presence of pyridine yields solid products, which have been characterized as ethyl benzal-cyanoacetate and its derivatives 1b-10b on the basis of elemental analysis and spectral studies. The reaction of 1a-10a with two moles of ethyl cyanoacetate also results in the formation of the same products 1b-10b, by an unexpected attack of ethyl cyanoacetate on azomethine linkage only rather than on both the reactive centres i.e. carbon-nitrogen double bond and carbon-oxygen double bond.
