2017-87-0Relevant academic research and scientific papers
Bromine-bromine interactions enhanced plasticity for the bending of a single crystal without affecting fluorescent properties
Paikar, Arpita,Podder, Debasish,Chowdhury, Srayoshi Roy,Sasmal, Supriya,Haldar, Debasish
, p. 589 - 593 (2019)
Ethyl 3-(3-bromo-4-methoxy-phenyl)-2-cyano-acrylate crystals exhibited very superior plasticity and shape persistent, self-standing properties compared to their non-bromo analogue. The crystal plasticity, controlled by a bromine-bromine interaction, has b
Synthesis of ionic liquid functionalized SBA-15 mesoporous materials as heterogeneous catalyst toward knoevenagel condensation under solvent-free conditions
Liu, Yong,Peng, Jiajian,Zhai, Shangru,Li, Jiayun,Mao, Jianjiang,Li, Meijiang,Qiu, Huayu,Lai, Guoqiao
, p. 2947 - 2949 (2006)
1-Methyl-3-propylimidazolium chloride (MPImCl) and 1-propylpyridinium chloride (PPyCl) ionic liquid functionalized SBA-15 mesoporous materials were synthesized and used as heterogeneous catalysts in Knoevenagel reactions with excellent yields and reusabil
A straightforward method for the synthesis of alkylidene and arylidene malonates through proline-catalyzed Knoevenagel condensation
Cardillo, Giuliana,Fabbroni, Serena,Gentilucci, Luca,Gianotti, Massimo,Tolomeklli, Alessandra
, p. 1587 - 1594 (2003)
A straightforward method for the synthesis of alkylidene/arylidene malonates and arylidene cyanoacetates, utilizing proline as an alternative to traditional catalysts is presented. A large number of unsaturated esters was obtained from the Knoevenagel reaction under very mild conditions and utilizing cheap reagents.
Ammonium chloride catalyzed Knoevenagel condensation in PEG-400 as ecofriendly solvent
Waghmare, Smita R.
, p. 849 - 855 (2021/09/28)
A simple and selective green methodology has been successfully developed for Knoevenagel condensation in polyethylene glycol-400 using 10 mol % ammonium chloride as catalyst. The method is applicable to a wide range of aromatic, heteroaromatic and α,β-unsaturated aldehydes. The reactions have been found to be clean and free from the formation of the Michael adduct.
A facile, efficient and solvent-free titanium (IV) ethoxide catalysed knoevenagel condensation of aldehydes and active methylenes
Ramaiah, Manjunatha M.,Shivananju, Nanjunda Swamy,Shubha, Priya Babu
, p. 107 - 115 (2020/02/04)
Titanium ethoxide has been employed as a novel and efficient reagent for the Knoevenagel condensation of aldehydes with active methylenes such as diethyl malonate and ethyl cyanoacetate under solvent free conditions to afford substituted olefins in high to excellent yields. The reaction is suitable for a variety of aromatic, aliphatic and heteroaromatic aldehydes with various active methylenes. Parallel to this, microwave irradiation has been utilized to achieve improved reaction rates and enhanced yields. Herein, we illustrated a convenient method for the preparation of α,β-unsaturated compounds using both conventional and microwave irradiation methods. An efficient and solvent free Knoevenagel condensation between aldehydes and active methylenes was developed using titanium ethoxide. The procedure proved to be successful with a wide range of substrates such as aromatic, aliphatic and heterocyclic aldehydes and various active methylenes to afford substituted olefins. The reaction was also carried out under microwave irradiation to accomplish the corresponding olefins with improved reaction rates, yields and cleaner reaction profiles.We have developed an efficient and novel methodology for the synthesis of olefinic compounds by Knoevenagel condensation under solvent-free conditions using titanium ethoxide, for the first time, as a reagent as well as a solvent. This method is appropriate for the synthesis of a variety of aromatic aldehydes containing various electron-donating and withdrawing groups, aliphatic and heteroaromatic aldehydes. The significant advantages offered by this methodology could be applied to various active methylenes in order to offer the corresponding Knoevenagel products. Thus, we believe that this method delivers high conversions, cleaner reaction profiles under solvent-free reaction conditions and shorter reaction times, all of which make it a very useful and attractive approach for the preparation of a wide range of substituted olefins.
Magnetic core-shell dendritic mesoporous silica nanospheres anchored with diamine as an efficient and recyclable base catalyst
Surabhi,Shabir, Javaid,Gupta, Padmini,Sah, Digvijay,Mozumdar, Subho
, p. 21152 - 21166 (2020/12/31)
In the present study, diamine-functionalized magnetic core-shell dendritic mesoporous silica nanospheres have been successfully synthesized by an oil-water biphasic stratification-coating strategy. The shape, size and morphology of the synthesized magnetic nanocatalyst could be characterized by various physicochemical techniques such as, field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The characteristic information about the successful immobilization of various functionalities on the nanospheres could be obtained with the help of X-ray powder diffraction (XRD) patterns, Fourier transform-infrared spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDX) and thermo-gravimetric analysis (TGA). The details about the magnetic behaviour and surface area of the nanocatalyst could be acquired by vibrating sample magnetometry (VSM) and BET surface analysis, respectively. The synthesized diamine-functionalized magnetic nanoparticles were then explored as a highly efficient catalyst for the Knoevenagel condensation and one-pot synthesis of polyhydroquinolines using aromatic/heteroaromatic aldehydes and aliphatic aldehydes with active methylene compounds under very mild conditions. The synthesized magnetic core-shell dendritic mesoporous silica nanospheres had large surface areas. This large surface area and pore volume could facilitate a proper interaction and penetration of the reactant molecules with the basic amine groups present on the dendritic mesoporous silica nanospheres. The supported nanocatalyst revealed no sign of leaching of the amine groups present inside the dendrimers and therefore, could be reused up to nine times without any noteworthy loss in catalytic activity.
Bismuth (III) Triflate: A Mild, Efficient Promoter for the Synthesis of Trisubstituted Alkenes through Knoevenagel Condensation
Datta, Arup
, p. 843 - 849 (2020/11/25)
In this work, smooth efficient and eco-friendly two component coupling method is reported for the synthesis of Knoevenagel Condensation product in presence of Bi(OTf)3 catalyst under solvent free condition. Catalyst has participated in condensation between substituted aldehydes (aromatic and hetero-aromatic) and active methylene compounds (ethyl cyanoacetate, malononitrile and cyanoacetamide) effectively to generate an excellent yield of the product. Bi(OTf)3 catalyst is stable, inexpensive and easily available was used for four times in this reaction without loss of catalytic activity. [Formula Presented]
The Modified Clay as a New and Eco-Friendly Catalyst for the Knoevenagel Reaction
Bentahar, S.,Dbik, A.,Khomri, M. El,Lacherai, A.,Messaoudi, N. El,Sabour, A.,Taleb, M. Ait
, p. 1438 - 1444 (2020/10/29)
Abstract: This work aims the synthesis of substituted alkenes via Knoevenagel condensation using the clay collected from the Agadir region and modified by KF as a heterogeneous catalyst (KF-modified clay). In this context, the influence of various paramet
Selenotungstates incorporating organophosphonate ligands and metal ions: synthesis, characterization, magnetism and catalytic efficiency in the Knoevenagel condensation reaction
Ban, Ran,He, Peipei,Kong, Hui,Ma, Pengtao,Niu, Jingyang,Wang, Jiawei,Wang, Jingping,Xu, Qiaofei,Yang, Zongfei
supporting information, p. 7420 - 7425 (2020/06/21)
Three sandwich-type TM-containing (TM = transition metal) organophosphonate-based polyoxotungstate clusters, [TM(H2O)4(SeW6O21)2{Co(OOCCH2NCH2PO3)2}3]12?(TM = Co, Ni), have been successfully synthesized, which are the first reported TM-containing organophosphonate-based selenotungstates. They were structurally characterized by PXRD analyses, IR spectroscopy, TGA analyses,etc. Magnetic measurements show that all three compounds exhibit antiferromagnetic interactions. Besides,Co1can be used as an efficient heterogeneous catalyst in the Knoevenagel condensation of benzaldehyde and ethyl cyanoacetate under mild conditions (60 °C), and exhibits satisfactory conversion (93%) and high selectivity (99%).
Water mediated procedure for preparation of stereoselective oximes as inhibitors of MRCK kinase
Luqman, Suaib,Misra, Krishna,Pandey, Jyoti,Shrivash, Manoj Kumar,Shukla, Akhilesh Kumar,Singh, Shilipi
, (2020/07/08)
Stereoselective aldoximes, preferably Z form have been obtained from α-cyano substituted carbonyl conjugated alkenes. This reaction occurs through Michael addition type reaction followed by retro-Knoevenagel reaction without transition-metal catalysis via C–C bond cleavage. These oximes are evaluated against cancer cell lines employing mechanistic study. Two oximes showed significant cytotoxic activity, which through in silico studies were found to inhibit MRCK Kinase, responsible for metastatic spread of cancer mortality.
