2700-22-3Relevant articles and documents
An excellently stable heterovalent copper–organic framework based on Cu4I4 and Cu(COO)2N2 SBUs: The catalytic performance for CO2 cycloaddition reaction and Knoevenagel condensation reaction
Jin, Feng
, (2020)
A novel 3D heterovalent Cu-based MOF, [Cu2Cu4I4(ANA)4(DMF)4]n (denoted as complex 1), was successfully designed and synthesized by the self-assembly of CuI and 5-aminonicotinic acid (HANA)
Synthesis of 5- and 7-(dicyanomethylene)-2,3-dihydrocyclohepta-1,4- dithiins, 'push-pull' heptafulvene derivatives. 8,8-Dicyanoheptafulvenes from α-bromomalononitrile and cycloheptatrienylium salt
Mori,Kubo,Takeshita
, p. 3742 - 3746 (1993)
Treatment of 2,3-dihydro-4aH-cyclohepta-1,4-dithiin with triphenylmethyl tetrafluoroborate followed by condensation with α-promomalononitrile in pyridine afforded 5- and 7-(dicyanomethylene)-2,3-dihydrocyclohepta-1,4- dithiins in good yields. When changing the solvent to acetonitrile, the products obtained were 5- and 6-(2,2-dicyanoethyl)-2,3-dihydro-1,4- benzodithiins. This new method was applicable to the general synthesis of dicyanoheptafulvenes from tropylium salts.
Knoevenagel condensation reaction catalysed by Al-MOFs with CAU-1 and CAU-10-type structures
Dhakshinamoorthy, Amarajothi,Heidenreich, Niclas,Lenzen, Dirk,Stock, Norbert
, p. 4187 - 4193 (2017)
The metal-organic frameworks (MOFs) CAU-1-NH2 ([Al4(OH)2(OCH3)4(p-BDC-NH2)3], (p-BDC-NH2)2- = 2-aminoterephthalate) and CAU-10-NH2 ([Al(OH)(m-BDC-NH2)], (m-BDC-NH2)2- = 5-aminoisophthalate) which possess two different pore sizes were studied for their catalytic activity as heterogeneous solid base catalysts in the Knoevenagel condensation reaction between benzaldehyde and malononitrile under mild reaction conditions (40 °C, 7 h, ethanol). For comparison, isoreticular MOFs containing a smaller amount of -NH2 groups (CAU-1-NH2/H) or no -NH2 groups (CAU-10-H) were synthesized. A two-step synthesis route including the synthesis of CAU-1-NH2 and its use as crystal seeds was developed to obtain the mixed-linker CAU-1-NH2/H compound. Only for CAU-1-NH2, up to 100% selectivity towards the desired Knoevenagel condensation product is observed. Hence, the catalytic activity of CAU-1-NH2 was tested between various benzaldehydes containing different substituents with malononitrile. By employing benzaldehyde and malononitrile as the starting materials, it is found that the mixed-linker MOF CAU-1-NH2/H catalyses the formation of the acetal (benzaldehyde diethyl acetal), while both CAU-10 materials lead to mixtures of the two products. Furthermore, the catalyst stability was also examined through reusability and leaching experiments and it is observed that the catalyst can be reused with no significant drop in its activity.
Chemical modification of crystal-like mesoporous phenylene-silica with amino group
Ohashi, Masataka,Kapoor, Mahendra P.,Inagaki, Shinji
, p. 841 - 843 (2008)
Amination of phenylene moieties in crystal-like mesoporous silica hybridized with phenylene is successfully achieved with close to 28% conversion of phenylene by a two-step chemical transformation process while preserving both the ordered mesostructure an
Nitrogen-rich porphyrinic metal-organic frameworks synthesized by postsynthetic metathesis: from inert material to active catalyst
Liu, Dahuan,Wang, Xuan,Chen, Ying-Pin,Yuan, Shuai,Zhong, Chongli,Zhou, Hong-Cai
, p. 975 - 979 (2016)
With the aid of a postsynthetic metathesis method, an inert nitrogen-rich porphyrinic metal-organic framework can exhibit a high catalytic activity in one-pot deacetalization-Knoevenagel condensation reaction.
Guanine-Derived Porous Carbonaceous Materials: Towards C1N1
Antonietti, Markus,Heil, Tobias,Kossmann, Janina,López-Salas, Nieves
, p. 6643 - 6650 (2020)
Herein, the basic nature of noble covalent, sp2-conjugated materials prepared via direct condensation of guanine in the presence of an inorganic salt melt as structure directing agent was studied. At temperatures below 700 °C stable and more basic additio
Au@Cu(II)-MOF: Highly Efficient Bifunctional Heterogeneous Catalyst for Successive Oxidation-Condensation Reactions
Wang, Jing-Si,Jin, Fa-Zheng,Ma, Hui-Chao,Li, Xiao-Bo,Liu, Ming-Yang,Kan, Jing-Lan,Chen, Gong-Jun,Dong, Yu-Bin
, p. 6685 - 6691 (2016)
A new composite Au@Cu(II)-MOF catalyst has been synthesized via solution impregnation and full characterized by HRTEM, SEM-EDS, XRD, gas adsorption-desorption, XPS, and ICP analysis. It has been shown here that the Cu(II)-framework can be a useful platform to stabilize and support gold nanoparticles (Au NPs). The obtained Au@Cu(II)-MOF exhibits a bifunctional catalytic behavior and is able to promote selective aerobic benzyl alcohol oxidation-Knoevenagel condensation in a stepwise way.
Phosphor-doped hexagonal boron nitride nanosheets as effective acid-base bifunctional catalysts for one-pot deacetalization-Knoevenagel cascade reactions
Zhao, Jun,Lin, Baining,Zhu, Yifan,Zhou, Yonghua,Liu, Hongyang
, p. 5900 - 5905 (2018)
One-pot cascade reactions over metal-free heterogeneous bifunctional catalysts have been attracting increased attention in green chemistry owing to the advantage of process intensification, as well as the elimination of wastes and metal contamination. In this paper, phosphor-doped hexagonal boron nitride nanosheets (BNP) can act as excellent metal-free acid-base bifunctional catalysts for one-pot deacetalization-Knoevenagel cascade reactions. XRD, FT-IR, XPS, and solid NMR characterizations indicate that phosphor was doped into the framework of h-BN mainly at the corner (N2PO) and bayer (N3P-OH) sites. The CO2-TPD and NH3-TPD characterizations showed that the BNP sample with optimal phosphor-doping amounts simultaneously possessed the highest amount of acid and base sites. When correlated with the catalytic performance, it can be concluded that mainly N3P-OH acts as the Br?nsted acid sites and -BNH2 and N2PO as the Lewis and Br?nsted base sites, respectively. In addition, the good recycling stability and immobilization feasibility on a monolith support confirm its potential in practical applications.
A layered amino-functionalized zinc-terephthalate metal organic framework: Structure, characterization and catalytic performance for Knoevenagel condensation
Tan, Yi,Fu, Zhiyong,Zhang, Jie
, p. 1966 - 1970 (2011)
A new stable mixed-ligand metal organic framework Zn2(tpt) 2(2-atp)I2 1 (tpt = tris (4-pyridyl) triazine, 2-atp = 2-aminoterephthalate) with split channels has been synthesized and characterized. The nitrogen containing ligands tpt and 2-atp are selected to create attractive basic sites for the catalyst. The Knoevenagel condensation between benzaldehyde and the active hydrogen compound (ethyl cyanoacetate or malononitrile) is carried out using compound 1 as solid basic catalytic support. The test results indicate that 1 is an efficient base catalyst with selective catalytic properties. It gives 37% and 99% yield respectively for the condensation products ethyl (E)-α-cyanocinnamate and 2- benzylidenemalononitrile. TG data show that the solid catalyst sample is fairly thermally stable. The compound does not show any signs of decomposition until 420 °C. PXRD data support that the catalyst remains its crystalline and framework stability after the catalysis process. These characters make it easily to be regenerated for the next cycle.
Lewis acid mediated three-component one-flask regioselective synthesis of densely functionalized 4-amino-1,2-dihydropyridines via cascade Knoevenagel/Michael/cyclization sequence This paper is dedicated to Professor Ganesh Pandey on the occasion of his 60th birthday
Koley, Suvajit,Chowdhury, Sushobhan,Chanda, Tanmoy,Janaki Ramulu,Samai, Subhasis,Motisa, Lerato,Singh, Maya Shankar
, p. 301 - 307 (2015)
A highly convergent and regioselective one-pot synthesis of hitherto unreported 4-amino-1,2-dihydropyridines has been achieved via three-component domino coupling (3CDC) of α-oxoketene-N,S-arylaminoacetals, aldehydes, and malononitrile in the presence of InCl3 under solvent-free conditions. The merit of this cascade Knoevenagel condensation/Michael addition/cyclization sequence is highlighted by its atom-economy, efficacy of forming consecutive three new bonds (two C-C and one C-N), and one ring in a single operation. Noteworthy, the presence of nitrile and amino groups at 3- and 4-positions of 1,2-dihydropyridine ring makes these compounds excellent precursors for further synthetic renovations. Remarkably, one of the newly synthesized 4-amino-1,2-dihydropyridine exhibited high selectivity and sensitivity for Fe3+ ion over other metal ions.
Synthesis, crystal structure and catalytic property of a highly stable 3D Cu(II)-organic framework
Chen, Chunyan
, (2020)
A three-dimensional (3D) Cu(II)-based MOF, [CuL·Cl]n (namely complex 1), was successfully generated through the in-situ reaction of CuCl2, NaN3, and 4-(4-cyanostyryl)pyridine. Notably, –CN and N3 ? ca
Photocatalytic cascade reactions and dye degradation over CdS-metal-organic framework hybrids
Chen, Yu-Zhen,Li, Shu-Rong,Ren, Feng-Di,Wang, Lin
, p. 35326 - 35330 (2021/11/30)
Two bifunctional CdS-MOF composites have been designed and fabricated. The hybrids exhibited synergistic photocatalytic performance toward two cascade reactions under visible light integrating photooxidation activity of CdS and Lewis acids/bases of the MO
A ru-complex tethered to a N-rich covalent triazine framework for tandem aerobic oxidation-knoevenagel condensation reactions
Abednatanzi, Sara,Der Voort, Pascal Van,Derakhshandeh, Parviz Gohari,Leus, Karen,Schmidt, Johannes,Watson, Geert
, (2021/06/12)
Herein, a highly N-rich covalent triazine framework (CTF) is applied as support for a RuIII complex. The bipyridine sites within the CTF provide excellent anchoring points for the [Ru(acac)2(CH3CN)2]PF6 complex. The obtained robust RuIII@bipy-CTF material was applied for the selective tandem aerobic oxidation-Knoevenagel condensation reaction. The presented system shows a high catalytic performance (>80% conversion of alcohols to α, β-unsaturated nitriles) without the use of expensive noble metals. The bipy-CTF not only acts as the catalyst support but also provides the active sites for both aerobic oxidation and Knoevenagel condensation reactions. This work highlights a new perspective for the development of highly efficient and robust heterogeneous catalysts applying CTFs for cascade catalysis.
Triazole-directed fabrication of polyoxovanadate-based metal-organic frameworks as efficient multifunctional heterogeneous catalysts for the Knoevenagel condensation and oxidation of alcohols
Cheng, Xueli,Han, Yinfeng,Hu, Changwen,Huang, Xianqiang,Li, Jikun,Mei, Yu,Wei, Chuanping
, p. 10082 - 10091 (2021/08/03)
By introducing 4-amino-1,2,4-triazole (4-NH2-trz), three new polyoxovanadate-based metal-organic frameworks (PMOFs) [Ni3(4-NH2-trz)6][V6O18]·3H2O (1), [Co3(4-NH2-trz)6][V6O18]·3H2O (2) and [Cu3OH(4-NH2-trz)3H2O][VO3]5·H2O (3) have been synthesized and thoroughly characterized by single-crystal X-ray diffraction (SXRD), powder X-ray diffraction (PXRD), infrared spectroscopy (FT-IR), thermogravimetric (TG) analysis and elemental analysis (EA). Among them, PMOFs1and2had similar structures containing [V6O18]6?clusters; however, PMOF3was isolated as a structure containing a [VO3]55?cluster when the amount of the 4-NH2-trz ligand was reduced to half with the other synthesis conditions being the same as those of PMOFs1and2except for the transition-metal chlorides. Furthermore, the negative charges of polyoxovanadate [V6O18]6?and [VO3]55?anions were balanced by trinuclear complex cations [Ni3(4-NH2-trz)6]6?for1, [Co3(4-NH2-trz)6]6?for2and [Cu3OH(4-NH2-trz)3H2O]5?for3, respectively. PMOFs1-3were further used as heterogeneous catalysts in the Knoevenagel condensation under solvent-free conditions and showed high catalytic activity. PMOF1showed moderate catalytic activities in the oxidation of various aromatic alcohols using H2O2as an oxidant. Moreover, PMOF1could be reused at least three times without losing its activity.
