15644-74-3Relevant articles and documents
Reductive Fragmentation of 9,9-Diarylfluorenes. Concurrent Radical Anion and Dianion Cleavage. Electron Apportionment in Radical Ion Fragmentations
Walsh, Thomas D.
, p. 1511 - 1518 (1987)
Both Radical anions and dianions of 9,9-diarylfluorenes cleave an aryl ring after reduction by alkali metals or naphtalenide radical anions in ether solvents.The relative amount of cleavage through each intermediate depends on the alkali metal cation, the solvent, and the presence or absence of 18-crown-6-ether.The tendency for dianion cleavage parallels that for disproportionation of radical anions to dianions and neutral hydrocarbons.Radical anion fragmentation is proposed to proceed via heterolytic cleavage in which electron flow is in the direction which offsets the charge distribution in the radical ion.In the present case, this initially affords 9-arylfluorenyl radical and aryl anion, which subsequently indergo electron exchange to form the more stable 9-arylfluorenyl anion and aryl radical.
One-Pass Conversion of Benzene and Syngas to Alkylbenzenes by Cu–ZnO–Al2O3 and ZSM-5 Relay
Han, Tengfei,Xu, Hong,Liu, Jianchao,Zhou, Ligong,Li, Xuekuan,Dong, Jinxiang,Ge, Hui
, p. 467 - 479 (2021/05/21)
Alkylbenzenes have a wide range of uses and are the most demanded aromatic chemicals. The finite petroleum resources compels the development of production of alkylbenzenes by non-petroleum routes. One-pass selective conversion of benzene and syngas to alkylbenzenes is a promising alternative coal chemical engineering route, yet it still faces challenge to industrialized applications owing to low conversion of benzene and syngas. Here we presented a Cu–ZnO–Al2O3/ZSM-5 bifunctional catalyst which realizes one-pass conversion of benzene and syngas to alkylbenzenes with high efficiency. This bifunctional catalyst exhibited high benzene conversion (benzene conversion of 50.7%), CO conversion (CO conversion of 55.0%) and C7&C8 aromatics total yield (C7&C8 total yield of 45.0%). Characterizations and catalytic performance evaluations revealed that ZSM-5 with well-regulated acidity, as a vital part of this Cu–ZnO–Al2O3/ZSM-5 bifunctional catalyst, substantially contributed to its performance for the alkylbenzenes one-pass synthesis from benzene and syngas due to depress methanol-to-olefins (MTO) reaction. Furthermore, matching of the mass ratio of two active components in the dual-function catalyst and the temperature of methanol synthesis with benzene alkylation reactions can effectively depress the formation of unwanted by-products and guarantee the high performance of tandem reactions. Graphic Abstract: [Figure not available: see fulltext.]
Selective catalytic synthesis of bio-based high value chemical of benzoic acid from xylan with Co2MnO4@MCM-41 catalyst
Fan, Minghui,He, Yuting,Li, Quanxin,Luo, Yuehui,Yang, Mingyu,Zhang, Yanhua,Zhu, Lijuan
, (2021/12/20)
The efficient synthesis of bio-based chemicals using renewable carbon resources is of great significance to promote sustainable chemistry and develop green economy. This work aims to demonstrate that benzoic acid, an important high added value chemical in petrochemical industry, can be selectively synthesized using xylan (a typical model compound of hemicellulose). This novel controllable transformation process was achieved by selective catalytic pyrolysis of xylan and subsequent catalytic oxidation. The highest benzoic acid selectivity of 88.3 % with 90.5 % conversion was obtained using the 10wt%Co2MnO4@MCM-41 catalyst under the optimized reaction conditions (80 °C, 4 h). Based on the study of the model compounds and catalyst's characterizations, the reaction pathways for the catalytic transformation of xylan to bio-based benzoic acid were proposed.
MOF-derived Ru@ZIF-8 catalyst with the extremely low metal Ru loading for selective hydrogenolysis of C–O bonds in lignin model compounds under mild conditions
Cao, Jing-Pei,Jiang, Wei,Xie, Jin-Xuan,Zhang, Chuang,Zhang, Jian-Li,Zhao, Liang,Zhao, Xiao-Yan,Zhao, Yun-Peng,Zhu, Chen
, p. 488 - 496 (2022/02/07)
Lignin hydrogenolysis to produce chemicals and biofuels is a challenge due to the stable C–O ether bond structure. Metal–organic framework (MOF) materials with excellent structural and chemical versatility have received widespread attention. Herein, a highly dispersed Ru metal anchored in functionalised ZIF-8 was fabricated by a general host–guest and reduction strategy. The Ru@ZIF-8 catalyst with a high specific surface area could efficiently promote the C–O bond cleavage of a variety of lignin model compounds under mild conditions. Compared with previous studies, the extremely low metal Ru loading in the Ru@ZIF-8 catalyst achieved a relatively higher activity. The introduction of Ru metal not only improved the dispersion of Zn metal, but also enhanced the electron density on the Zn surface, suggesting a high catalytic performance. It was more conducive for the Ru@ZIF-8 catalyst to exhibit the C–O bond cleavage activity when in the presence of both H2 and isopropanol. An investigation of the mechanism revealed that the direct hydrogenolysis of benzyl phenyl ether was the main reaction pathway.
