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Alkenes and Alkynes: Structure, Nomenclature, and Reactions
Published in Michael B. Smith, A Q&A Approach to Organic Chemistry, 2020
Alkene (a) has an 8-carbon chain containing the double bond with an ethyl substituent. The name is, therefore, 3-ethyloct-3-ene. Alkene (b) is a cyclic 6-carbon alkene and is called cyclohexene. Numbering for the geminal dimethyl groups (both methyl groups on the same carbon) gives the lowest number 4,4-dimethylcyclohexene (remembering that C1 and C2 of cyclohexene must contain C=C). Alkene (c) is a 7-carbon chain containing one Br, two methyls, and one ethyl. The name is 2-bromo-3-ethyl-4,6-dimethylhept-1-ene. Alkene (d) is a cyclooctene with a methyl and an ethyl group. Since the groups are named and numbered alphabetically, this is 1-ethyl-2-methylcyclooctene.
Synthesis and characterization of naphthaldiimine-based ruthenium(III) complexes; homogenous catalytic hydrogenation and isomerization of internal and terminal alkenes
Published in Journal of Coordination Chemistry, 2022
Ahmed M. Fathy, Mahmoud M. Hessien, Mohamed M. Ibrahim, Abd El-Motaleb M. Ramadan
Hydrogenation and isomerization processes in a single-vessel catalytic reaction has generated great interest in academia and industry [60]. The present catalysts were employed in the catalytic hydrogenation and isomerization processes of 1-hexene. The catalytic hydrogenation experiments were performed in a similar manner to cyclohexene. The data in Table 15 indicate that Ru(III) complexes under study catalyzed the hydrogenation of 1-hexene without significant difference in activity, as in the case of cyclohexene hydrogenation. The difference from the case of cyclohexene is that the catalytic hydrogenation of 1-hexene led to several products while a single product, cyclohexane, was observed for cyclohexene.
Activated carbon supported Co1.5PW12O40 as efficient catalyst for the production of 1, 2 cyclohexane diol by oxidation of cyclohexene with H2O2 in the presence of CO2
Published in Green Chemistry Letters and Reviews, 2020
Ramyah Radman, Ahmed Aouissi, Abdullah A. Al-Kahtani, Wafa K. Mekhamer, A. Yacine Badjah Hadj Ahmed
The catalytic activity of the AC-CoPW-x was evaluated for the reaction of the dihydroxylation of cyclohexene. The experiments were carried out under a CO2 pressure of 0.5 MPa at 70°C during 4 h. The reaction products were analyzed by GC and GC-MS. The results showed that 1, 2-cyclohexanediol was obtained as major product. 2-cyclohexen-1-one and 2-cyclohexen-1-ol (abbreviated as diol, enone and enol respectively) were obtained as minor products. Cyclohexene oxide (abbreviated as epoxide), cyclohexanol, 1, 2-cyclohexanedione, 3-hydroxy cyclohexanone and 1,2,3-cyclohexanetriol are observed as traces.
Benzene hydrogenation over polydopamine-modified MCM-41 supported Ruthenium-Lanthanum catalyst
Published in Inorganic and Nano-Metal Chemistry, 2018
Hongguang Liao, Yanjuan Xiao, Xiaoguang Yu, Xuanyan Liu, Hongmei Zhong, Meidong Liang, Haoyan He
Numerous literatures have reported liquid phase hydrogenation of benzene to cyclohexene over unsupported ruthenium-based alloy catalyst [6–12] or supported ruthenium-based catalyst.[13–28] Nevertheless, Asahi Chemical Industry Co. is the only one who has succeeded in the commercialization of the process for producing cyclohexene from benzene hydrogenation over metallic ruthenium-zinc particles catalyst.[29] From the point of view of thermodynamic analysis, benzene hydrogenation tends to produce cyclohexane which has smaller standard formation free-energy than cyclohexene.[30] Previous researches have shown that the key point for benzene hydrogenation to cyclohexene with high selectivity lies in how to promote the desorption of the produced cyclohexene from the ruthenium-based catalyst and inhibit its absorption so as to prevent the further hydrogenation to cyclohexane. Unsupported Ru–Zn catalysts were prepared and tested for benzene hydrogenation in the solution of ZnSO4 and diethanolamine.[31] The synergism of diethanolamine and ZnSO4 can enhance the hydrophilicity of the catalyst and stabilize the formed cyclohexene, thus increasing the selectivity to cyclohexene. For improving the utilization rate of noble ruthenium metal and catalyst lifetime, the development of the efficient supported ruthenium-based catalyst has been the research focus in the field of partial hydrogenation of benzene. The hydrophilic supports are more likely to form a stagnant water layer on its surface which may promote the desorption of the formed cyclohexene and inhibit its absorption.[8] Suppino et al. have investigated the effects of organic additives on the partial hydrogenation of benzene over Ru/Al2O3 and Ru/CeO2 catalysts.[19] The effects of additives based on the interactions between additives and catalyst and also between the additives and the stagnant water film on the surface of Ru were discussed. The organic additives containing N atoms may bond to the Ru active sites to block the planar adsorption of benzene and lower the activity. And the presence of the additives with hydroxyl groups may enhance the hydrophilicity around the ruthenium particles to increase the yield of cyclohexene.