87-41-2Relevant articles and documents
Acid-tolerant intermetallic cobalt-nickel silicides as noble metal-like catalysts for selective hydrogenation of phthalic anhydride to phthalide
Zhang, Liangliang,Chen, Xiao,Chen, Yujing,Peng, Zhijian,Liang, Changhai
, p. 1108 - 1116 (2019)
Chemoselective hydrogenation of phthalic anhydride is regarded as the most promising route for producing downstream high-performance phthalide. A series of intermetallic cobalt-nickel silicide catalysts embedded in a carbon matrix (CoxNi2-xSi@C) with acid-tolerance prepared by microwave-assisted chemical vapor deposition have been investigated in this reaction system. Activity measurements show a remarkable positive synergistic effect, forming a volcano-shaped plot over the nominal Co metal fraction for CoxNi2-xSi@C catalysts with a peak at x = 1.5, which corresponds to a 4.5-fold enhancement of the yield of phthalide over Co2Si@C and a 2.0-fold enhancement over the Ni2Si@C monometallic silicide catalysts, which can be correlated with the interaction of cobalt-nickel and metal-silicon bonds. In addition, the cobalt-rich bimetallic silicide exhibits an equal activity to the reference noble metal catalysts (Au, Pd, and Pt) and a significantly higher activity than transition metal catalysts. Moreover, the bimetallic silicide as an intermetallic compound catalyst has demonstrated robust acid corrosion resistance compared to the corresponding metal catalysts.
Catalytic enantioselective intramolecular Tishchenko reaction ofmeso-dialdehyde: synthesis of (S)-cedarmycins
Ismiyarto,Kishi, Nobuki,Adachi, Yuki,Jiang, Rui,Doi, Takahiro,Zhou, Da-Yang,Asano, Kaori,Obora, Yasushi,Suzuki, Takayoshi,Sasai, Hiroaki,Suzuki, Takeyuki
, p. 11606 - 11609 (2021)
The first successful example of a catalytic enantioselective intramolecular Tishchenko reaction of ameso-dialdehyde in the presence of a chiral iridium complex is described. Chiral lactones were obtained in good yields with up to 91% ee. The obtained enantioenriched lactones were utilized for the first synthesis of (S)-cedarmycins A and B.
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Harrison et al.
, p. 5793 (1970)
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Hamaguchi,Ibata
, p. 287 (1976)
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Strong base catalysis of sulfated mesoporous alumina for the Tishchenko reaction in supercritical carbon dioxide
Seki, Tsunetake,Onaka, Makoto
, p. 262 - 263 (2005)
Heterogeneous strong base catalysis for the Tishchenko reaction in acidic scCO2 solvent has been realized with mesoporous alumina modified with SO42-, while a conventional solid base like CaO showed almost no catalytic performance in scCO2. Copyright
An efficient carbonylation of aryl halides catalysed by palladium complexes with phosphite ligands in supercritical carbon dioxide
Kayaki, Yoshihito,Noguchi, Yushi,Iwasa, Seiji,Ikariya, Takao,Noyori, Ryoji
, p. 1235 - 1236 (1999)
The carbonylation of aryl halides catalysed by CO2 soluble Pd complexes with trialkyl or triaryl phosphite ligands proceeds rapidly in scCO2, in which the rate of the reaction is higher than those attained in solution phase reactions.
(Diacetoxyiodo)benzene-mediated oxygenation of benzylic C(sp3)-H bonds with N-hydroxyamides at room temperature
Qian, Peng-Cheng,Liu, Yu,Song, Ren-Jie,Hu, Ming,Yang, Xu-Heng,Xiang, Jian-Nan,Li, Jin-Heng
, p. 1680 - 1684 (2015)
A new, metal-free method for the formation of C(sp3)-O bonds was established by PhI(OAc)2-mediated oxygenation of benzylic C(sp3)-H bonds with N-hydroxyamides at room temperature, in which the C(sp3)-H oxidation is activated by a polyflurophenylamide group.
Integration of Earth-Abundant Photosensitizers and Catalysts in Metal-Organic Frameworks Enhances Photocatalytic Aerobic Oxidation
Feng, Xuanyu,Pi, Yunhong,Song, Yang,Xu, Ziwan,Li, Zhong,Lin, Wenbin
, p. 1024 - 1032 (2021/01/26)
We report here the construction of two metal-organic frameworks (MOFs), Zr6-Cu/Fe-1 and Zr6-Cu/Fe-2, by integrating earth-abundant cuprous photosensitizers (Cu-PSs) and Fe catalysts for photocatalytic aerobic oxidation. Site isolation and pore confinement stabilize both Cu-PSs and Fe catalysts, while the proximity between active centers facilitates electron and mass transfer. Upon visible light irradiation and using O2 as the only oxidant, Zr6-Cu/Fe-1 and Zr6-Cu/Fe-2 efficiently oxidize alcohols and benzylic compounds to afford corresponding carbonyl products with broad substrate scopes, high turnover numbers of up to 500 with a 9.4-fold enhancement over homogeneous analogues, and excellent recyclability in four consecutive runs. Control experiments, spectroscopic evidence, and computational studies revealed the photo-oxidation mechanism: Oxidative quenching of [Cu-PS]? by O2 affords [CuII-PS], which efficiently oxidizes FeIII-OH to generate a hydroxyl radical for substrate oxidation. This work highlights the potential of MOFs in promoting earth-abundant metal-based photocatalysis.
Cu2O-CuO/Chitosan Composites as Heterogeneous Catalysts for Benzylic C?H Oxidation at Room Temperature
Kanarat, Jurin,Bunchuay, Thanthapatra,Klysubun, Wantana,Tantirungrotechai, Jonggol
, p. 4833 - 4840 (2021/10/07)
Recently, in catalysis, chitosan has been exploited as a macrochelating ligand for metal active species due to the presence of various functional groups in its structure. Moreover, copper-based catalysts are classified as one of the most environmentally friendly catalytic systems and their use for the oxidation of alkylarene has not been established much. Therefore, in this work, the hydrothermal synthesis of copper oxide-chitosan composites as heterogeneous catalysts for the benzylic C?H oxidation of alkylarene was investigated. Characterization results reveal mixed phases of CuO and Cu2O, inferring the ability of chitosan to act as a reducing sugar under the hydrothermal condition. The pre-existing interaction between copper species and chitosan as well as the co-existence of the Cu2O and CuO structures give rise to the efficient performance of the catalysts. The synthesized composites exhibit high activity for the oxidation of fluorene to 9-fluorenone at room temperature and small catalyst loading (1 mol % of Cu, >90 % conversion and 100 % selectivity). Superior TOF was observed, and a good scope of substrates can be converted to corresponding ketones in 48–97 % yields with these copper oxide-chitosan catalysts. In addition, the catalysts can be used for up to nine cycles without significant decrease of the activity.