3695-83-8Relevant academic research and scientific papers
Microwave-Assisted, Ni-Induced Fabrication of Hollow ZIF-8 Nanoframes for the Knoevenagel Reaction
Zhang, Pengfang,Xiao, Yun,Sun, Hui,Dai, Xiaoping,Zhang, Xin,Su, Haixia,Qin, Yuchen,Gao, Daowei,Jin, Axiang,Wang, Hai,Wang, Xiubing,Sun, Shigang
, p. 3841 - 3850 (2018)
Morphology-controlled synthesis of metal-organic frameworks (MOFs) is of tremendous importance to understand the morphology-structure-property relationships. Although great emphasis has been placed on the controllable synthesis of MOFs, the preparation of hollow and nanoframe-like MOFs, especially using the microwave irradiation method, remains a great challenge. In the present work, we report microwave-assisted synthesis of hollow butterfly and ring zeolitic imidazolate framework-8 (ZIF-8) with the stimuli of Ni ions. Interestingly, the sphere, butterfly, and fiber ZIF-8 catalysts were also fabricated when adjusting the weight ratio of Zn and Ni resources. Specifically, sphere, butterfly, hollow butterfly, and ring particles have maintained the ZIF-8 structure. On the basis of the time sequential experiments, we inferred that the formation of hollow butterfly and ring particles is driven by the change of surface energy. The Knoevenagel reaction was carried out to explore the catalytic activity of these ZIF materials. The ring particles with ZIF-8 structure showed the highest catalytic activity. The open structure, thin walls, and the amount of basicity have been extensively discussed to shed light on the superior catalytic performance of ring particles.
Highly Active Bisamino Functionalized Zr(IV)-UiO-67 Metal-Organic Framework for Cascade Catalysis
Das, Aniruddha,Anbu, Nagaraj,Mostakim,Dhakshinamoorthy, Amarajothi,Biswas, Shyam
supporting information, p. 2830 - 2834 (2020/07/04)
This work reports the synthesis and characterization of Zr(IV)-based UiO-67-(NH2)2 (called 1) metal-organic framework. Activated 1 (named 1') was shown to be an efficient tandem catalyst in the conversion of benzaldehydedimethyl acet
Preparation of O-Protected Cyanohydrins by Aerobic Oxidation of α-Substituted Malononitriles in the Presence of Diarylphosphine Oxides
Zhang, Dapeng,Lian, Mingming,Liu, Jia,Tang, Shukun,Liu, Guangzhi,Ma, Cunfei,Meng, Qingwei,Peng, Haisheng,Zhu, Daling
supporting information, p. 2597 - 2601 (2019/04/17)
A mild, reagent-cyanide-free, and efficient synthesis of O-phosphinoyl-protected cyanohydrins from readily available α-substituted malononitriles was realized using diarylphosphine oxides in the presence of O2. Mechanistic studies indicated that in addition to the initial aerobic oxidation of the malononitrile derivative notable features of this process include the formation of a tetrahedral intermediate and a subsequent intramolecular rearrangement. The phosphinoyl-protecting group can be removed by alcoholysis or by reduction with DIBAL-H.
Mechanically fabricated Metal–organic framework/resin composite nanoparticles for efficient basic catalysis
Zhang, Zhi-Hui,Qian, Bing-Bing,Sheng, Pan-Pan,Yang, Sen,Huang, Xian-Feng,Wang, Jin-Long,Chen, Qun,Wang, Liang,He, Ming-Yang
, (2019/01/16)
Zeolitic imidazolate framework-8 (ZIF-8) was successfully composited with an anionic basic resin 201?×?7 (717-resin) to provide a novel ZIF-8/717-resin composite. Its catalytic activity toward the Knoevenagel condensation reaction was evaluated. Results s
Controlling, Understanding, and Redirecting the Thermal Rearrangement of 3,3-Dicyano-1,5-enynes
Scott, Sarah K.,Sanders, Jacob N.,White, Katherine E.,Yu, Roland A.,Houk,Grenning, Alexander J.
supporting information, p. 16134 - 16139 (2018/11/27)
The thermal [3,3] rearrangement of 3,3-dicyano-1,5-enynes to γ-allenyl alkylidenemalononitriles (the "enyne Cope rearrangement") has largely eluded synthetic value as the desired products, too, are thermally reactive and ultimately yield 6π electrocycliza
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 (2017/08/04)
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.
Superacid-catalyzed intramolecular cyclization reaction of arylcyanopropionate: Geminal substitution effect on superelectrophilicity
Nakamura, Satoshi,Sugimoto, Hiromichi,Ohwada, Tomohiko
, p. 4219 - 4224 (2008/09/20)
(Chemical Equation Presented) We present superacid-catalyzed intramolecular cyclization reactions of arylcyanopropionates to give cyclized five- and six-membered β-enamino esters in moderate to high yields. Known intramolecular ring-closing reactions of protonated nitrile to aromatic carbon atom are limited to the 6-membered case. Interestingly, a significant synergistic increase of reactivity of the cyano functionality was observed, and the cyano nitrogen atom was converted into an amino group, when an ester group was present in a geminal arrangement. Deuterium exchange experiments excluded the involvement of deprotonation of the α-proton in the cyclization process. The acidity dependence of the cyclization reactions and 13C NMR studies of a model compound, methyl cyanoacetate, in various acidic media were consistent with the involvement of the O,N-diprotonated dication of methyl cyanoacetate, a distonic dication, in strong acid, and this is considered to be the de facto electrophile in the present cyclization reaction of arylcyanopropionates.
