22440-82-0Relevant articles and documents
Facile Fabrication of Nickel/Heazlewoodite@Carbon Nanosheets and their Superior Catalytic Performance of 4-Nitrophenol Reduction
Wang, Xinyu,Lu, Jing,Zhao, Yunlong,Wang, Xiaopeng,Lin, Zhang,Liu, Xueming,Wu, Ronglan,Yang, Chao,Su, Xintai
, p. 4143 - 4153 (2018)
A facile molten salt method was utilized for the synthesis of carbon anchored nickel/heazlewoodite nanoparticles (Ni/Ni3S2@C nanosheets) with potassium humate as the carbon and sulfur source and NaCl as template. The morphology, particle size and crystallinity of the products were characterized by various techniques containing TEM, FE-SEM and XRD. Furthermore, the mesoporous Ni/Ni3S2@C own easy accessibility of active sites and high surface area (149.04 m2 g?1). Thus, the as-prepared Ni/Ni3S2@C exhibited prominent performance for catalytic reduction of 4-nitrophenol (4-NP). Catalytic reduction of other nitrophenols (NPs) were also tested which can prove that the catalyst own selectivity on reduction of NPs. For durability, the property of the catalyst does not decrease obviously after five cycles. More significant correlations concerning effect of activation parameters (Ea=37.21 kJ mol?1) on 4-NP reduction were scrutinized and discussed. Hence, we provide a facile method for fabrication of metal/metal sulfide@C which own better dispersity, small dimension and excellent catalytic performance for further studies.
Scope and Optimization of the Double Knorr Cyclization: Synthesis of Novel Symmetrical and Unsymmetrical Tricyclic 1,8-Diazaanthraquinones
Prior, Allan M.,Sun, Dianqing
supporting information, p. 859 - 871 (2018/02/10)
The Knorr cyclization of β-ketoanilides to form 2-quinolones in the presence of acid is well documented chemistry. Double Knorr cyclization is rare, with very few examples appearing in the literature to date. The double Knorr methodology can provide access to tricyclic 1,8-diazaanthraquinones, a scaffold seen in the diazaquinomycin family. The optimized synthesis of diazaquinomycin A and structural analogues thereof via double Knorr cyclization of di-β-ketoanilide precursor substrates is reported. The scope and generality of the double Knorr cyclization were investigated along with an optimization study. The double Knorr cyclization was found to be sensitive to steric bulk on precursor substrates. In addition, the presence of a 5-hydroxy group on the 1,3-di-β-ketoanilide facilitated the double Knorr cyclization, possibly due to its stabilizing effect on the carbocation intermediates formed during the reaction.
Palladium Supported on Graphitic Carbon Nitride: An Efficient and Recyclable Heterogeneous Catalyst for Reduction of Nitroarenes and Suzuki Coupling Reaction
Zhao, Yukai,Tang, Ruiren,Huang, Rong
, p. 1961 - 1971 (2015/12/24)
In this study, a novel platelet-like nanocatalyst, Pd/g-C3N4 with easily approachable active sites, was developed. The mesoporous graphitic carbon nitride (g-C3N4) is a layered structure connected by planar amino groups, which can work as stabilizer and active support for noble metal nanoparticles. The palladium nanoparticles with an average particle size of 3.25 nm were evenly dispersed on the surface of g-C3N4 without aggregation. Detailed charaterizations reveal that there is no covalent-bond interaction between g-C3N4 and Pd NPs. The Pd/g-C3N4 catalyst showed excellent catalytic activity in the reduction of nitroarenes by NaBH4, and Suzuki coupling reaction of aryl halides with arylboronic acids under mild conditions. The reduction of 4-nitrophenol has a pseudo-first-order rate constant of 7.29 × 10-3 s-1, and an activity parameter of 1.37 s-1 mM-1, which is higher than those reported in the literature. Furthermore, the Suzuki coupling reactions processed smoothly with 97.0 % isolate yield in less than 30 min in water with PEG600 as the additive. The catalyst could be recycled for five times without significant loss of catalytic activity, which confirmed the good stability of the catalyst. Graphical Abstract: [Figure not available: see fulltext.]
