24854-67-9Relevant academic research and scientific papers
An efficient epoxidation of terminal aliphatic alkenes over heterogeneous catalysts: When solvent matters
Palumbo,Tiozzo,Ravasio,Psaro,Carniato,Bisio,Guidotti
, p. 3832 - 3839 (2016/06/13)
The epoxidation of unfunctionalized terminal aliphatic alkenes over heterogeneous catalysts is still a challenging task. Due to the tuning of a peculiar catalyst/oxidant/solvent combination, it was possible to attain good alkene conversions (73%) and excellent selectivity values (>98%) in the desired terminal 1,2-epoxide. Over the titanium-silica catalyst and in the presence of tert-butylhydroperoxide, the use of α,α,α-trifluorotoluene as an uncommon non-toxic solvent was the key factor for a marked enhancement of selectivity. The titanium-silica catalyst was efficiently recycled and reused after a gentle rinsing with fresh solvent.
A surfactant-like ionic liquid with permanganate dissolved as a highly selective epoxidation system
Lu, Yu-Jing,Wong, Wing-Leung,Chow, Cheuk-Fai
, p. 25 - 28 (2015/06/08)
A ligand-free catalytic epoxidation system using permanganate in a surfactant-like ionic liquid (IL) medium was developed. The results indicate that the IL takes crucial effects in the epoxide selectivity. The loading of permanganate is also found critical in preventing over-oxidation of epoxides. The system with 0.3 mol% permanganate and 3.5-equivalent CH3CO3H is able to achieve excellent yields and selectivity of epoxides. The study of epoxidation with KMnO4 in IL medium reveals an unusual oxidation behavior of permanganate not found in traditional solvents.
Manganese acetate in pyrrolidinium ionic liquid as a robust and efficient catalytic system for epoxidation of aliphatic terminal alkenes
Ho, Kam-Piu,Wong, Wing-Leung,Lee, Lawrence Yoon Suk,Lam, Kin-Ming,Chan, Tak Hang,Wong, Kwok-Yin
experimental part, p. 1970 - 1973 (2011/04/15)
Green epoxides! A novel and simple ionic liquid/manganese acetate catalytic system has been developed for the rapid and selective oxidation of aliphatic terminal alkenes to epoxides. It provides an efficient, reusable, and scalable protocol for the green synthesis of epoxides from various aliphatic terminal alkenes.
Structure-property relationships in metallosurfactants
Griffiths, Peter C.,Fallis, Ian A.,James, Craig,Morgan, Ian R.,Brett, Gemma,Heenan, Richard K.,Schweins, Ralf,Grillo, Isabelle,Paul, Alison
experimental part, p. 1981 - 1989 (2011/10/31)
The morphology of micelles formed by three sub-classes of metallosurfactants - those with macrocyclic, linear and gemini head groups - has been studied by small-angle neutron scattering (SANS) for a series of metal- and counter-ions. All the data may be described by a model that invokes a globular micelle morphology in which the dimensions of the micelle are consistent with the known chemical structure of the constituent groups within the metallosurfactant. For two macrocyclic head group metallosurfactants, viz. 1-(2-hydroxy-tetradecyl)-1,4,7-triazacyclonane that forms predominantly spherical micelles and 1-(2-hydroxy-tetradecyl)-1,4,7,10-tetraazacyclononane that forms disc-like micelles, the metal ion and its counter-ion have a negligible effect on the morphology of the micelle. Binary mixtures of surfactants with these two macrocyclic head groups (with homo- or hetero-metal ions/counter-ions) form mixed micelles whose morphology is an average of the two single component micelles. Further, as found for the single surfactant solutions, the metal and counter-ion had no effect on the morphology of the mixed surfactant micelle. Lastly, the micelle morphology of two gemini surfactants was also shown to be insensitive to the number and nature of the metal and counter-ions present, but sensitive to the structure of the head group. These observations considerably extend our understanding of the relationship between chemical structure and micelle morphology for these interesting molecules.
A simple and effective catalytic system for epoxidation of aliphatic terminal alkenes with manganese(II) as the catalyst
Ho, Kam-Piu,Wong, Wing-Leung,Lam, Kin-Ming,Lai, Cheuk-Piu,Chan, Tak Hang,Wong, Kwok-Yin
experimental part, p. 7988 - 7996 (2009/11/30)
A simple catalytic system that uses commercially available manganese(II) Perchlorate as the catalyst and peracetic acid as the oxidant is found to be very effective in the epoxidation of aliphatic terminal alkenes with high product selectivity at ambient temperature. Many terminal alkenes are epoxidised efficiently on a gram scale in less than an hour to give excellent yields of isolated product (>90%) of epoxides in high purity. Kinetic studies with some C9-alkenes show that the catalytic system is more efficient in epoxidising terminal alkenes than internal alkenes, which is contrary to most commonly known epoxidation systems. The reaction rate for epoxidation decreases in the order: 1-nonene>cis-3-nonene> trans-3-nonene. ESI-MS and EPR spectroscopic studies suggest that the active form of the catalyst is a high-valent oligonuclear manganese species, which probably functions as the oxygen atomtransfer agent in the epoxidation reaction.
