173541-54-3Relevant academic research and scientific papers
Spherosilicates with peripheral malonic acid and vinyl end groups
Shen, Zhongliang,Kim, Jongsik,Shen, Jingmei,Downing, Christopher M.,Lee, Sungsik,Kung, Harold H.,Kung, Mayfair C.
, p. 3357 - 3359 (2013)
Two novel spherosilicates comprised of an octahedral Si8O 12 core, [Si8O12]-(OSiMe2CH 2CH2CH2CH(COOH)2)8 and [Si8O12]-(OSiMe2CH2CH 2CH2CH(COOSi(CHCH2)3) 2)8, were synthesized from [Si8O 12]-(OSiMe2H)8. These new structures have high densities of peripheral functional groups, and the second structure also possesses silyl ester bonds that are easily cleavable under mild conditions. These functionalities enable these structures to be modified further and to have many potential applications. We demonstrated one by cross-linking the vinyl-terminated spherosilicate to form nanospheres with a narrow size distribution and utilizing the hydrophilic interior to accommodate a Pd salt in a toluene solution. The Royal Society of Chemistry 2013.
A Useful Oxidation Procedure for the Preparation of 3-Alkanoyltetronic Acids
Mittra, Asmita,Yamashita, Masayuki,Kawasaki, Ikuo,Murai, Hiromichi,Yoshioka, Tomomichi,Ohta, Shunsaku
, p. 909 - 910 (1997)
An easy and convenient synthesis of 3-alkanoyl-5-hydroxymethyltetronic acids, the salts of which have inhibitory activity against HIV-1 protease, is described and a new direct route to 1,3-dicarbonylester from cyclic β-ketoester is developed.
Supported cobalt oxide nanocrystals: Morphology control and catalytic performance for styrene oxidation
Wang, Zhen,Hou, Xianliang,Shen, Jingmei,Li, Tiehu
, p. 89503 - 89509 (2016)
Metal oxide nanoparticles with controlled size and morphology seem extremely important due to the strong correlation between these parameters and their catalytic properties. Herein supported cobalt oxide nanoparticles with controlled size and different morphologies were successfully synthesized via a facile hydrothermal synthetic route under mild conditions. The size and morphology of the products can be readily tuned by tuning process parameters such as hydrothermal time and hydrothermal temperature. As synthesized supported cobalt oxide nanoparticles, namely Co3O4-150, Co3O4-550 and Co3O4-650, were quite active in the catalytic oxidation of styrene with H2O2 as a green oxidant. However, due to the size and morphology differences, these supported cobalt oxide nanoparticles exhibited different activities and selectivities. Co3O4-550 resulted in higher activity while Co3O4-650 exhibited relatively higher selectivity to epoxide. Moreover, these cobalt catalysts could be recycled, indicating this to be a promising method of fabricating supported cobalt oxide catalysts for the oxidation of olefins in large-scale processes.
Enantioselective Isothiourea-Catalysed Michael-Michael-Lactonisation Cascade Reaction for the Synthesis of δ-Lactones and 1,2,3,4-Substituted Cyclopentanes
Robinson, Emily R. T.,Frost, Aileen B.,Elías-Rodríguez, Pilar,Smith, Andrew D.
, p. 409 - 423 (2016/12/24)
This manuscript describes the application of α,β-unsaturated acyl ammonium intermediates in a Michael-Michael-lactonisation cascade process to furnish δ-lactones. Generation of α,β-unsaturated acyl ammonium intermediates was achieved upon addition of isothiourea catalyst HyperBTM into α,β-unsaturated acid chlorides. Subsequent reaction with enone-malonates gave access to δ-lactones in 20-64% yield, 72.5:27.5 to 95:5 er and 81:19 to >95:5 dr. Additionally, application of a ring-opening protocol yielded 1,2,3,4-substituted cyclopentanes in 28-77% yield, 76:24 to 98:2 er and 86:14 to >95:5 dr. Interestingly, the highest er was observed at high reaction temperatures, with 70°C proving optimal. This effect was investigated by conducting an Eyring analysis, which indicated that differential activation entropy rather than differential activation enthalpy is responsible for enantiodiscrimination in this process.
One-pot cycloisomerization/hetero-diels-alder reaction of 1,6-enynes with aldehydes catalyzed by rhodium and a Bronsted acid
Ishida, Mana,Tanaka, Ken
supporting information, p. 2120 - 2123 (2013/06/05)
A rhodium and Bronsted acid catalyzed one-pot cycloisomerization/ hetero-Diels-Alder reaction of 1,6-enynes with unactivated aldehydes was established under mild conditions. This one-pot catalytic protocol produced a wide variety of annulated dihydropyrans from readily available starting materials in a highly atom economical manner.
