Highly enantioselective olefin epoxidation controlled by helical confined environments

作者：Fernandes Cristina I; Saraiva Marta S; Nunes Teresa G; Vaz Pedro D^*; Nunes Carla D

来源：Journal of Catalysis, 2014, 309: 21-32.

DOI：10.1016/j.jcat.2013.08.032

• Asymmetric catalysis
• Chiral recognition
• Helical materials
• Molybdenum
• Olefin epoxidation
• Stereoselectivity
• Mesoporous materials
• Oxidation catalysis

Helical mesoporous materials of the MCM-41 type are important materials that can be prepared by onepot synthesis procedures with a co-surfactant. A control of the characteristics at a local level is of the most important in the view of the applications of such materials. However, there are not many studies relating such features `with synthetic approaches. In this work, we prepared both helical and regular channel materials from Si-based MCM-41 type. Afterward, a bpy derivative was used as ligand to coordinate The complexes and the new materials were tested as the catalytic precursors in the epoxidation of cis-cyclooctene, styrene, 1-octene, R-(+)-limonene and trans-hex-2-en-1-ol, using tertbutylhydroperoxide (TBHP) as oxidant. Although almost all the catalysts were 100% selective toward the epoxide, the conversions were in general good. The major achievement of these catalysts is an outstanding stereocontrol of the reaction products. In addition, these catalysts were found to be very effective under several circumstances. This is certainly an important contribution for such concept and may render such materials further applications where chiral recognition is important.

• 出版日期2014-1