Abstract
A novel chiral sulphonato-salen-manganese (111) complex has been prepared and intercalated into a Zn-Al layered-double hydroxide (LDH) structure. The resulting catalyst was found to be highly active and enantioselective in the epoxidation of various styrenes and cyclic alkenes when using a combination of pivalaldehyde and molecular oxygen at atmospheric pressure and room temperature. At 94% conversion, 1-methyl-1-cyclohexene could be converted to epoxide with 68% ee and 90% selectivity with a turnover frequency (TOF) of 234 h(-1), whereas 4-methyl-styrene was converted with 62% ee and 70% selectivity with a TOF of 327 h-1. In the case of styrenes and cyclic alkenes, TOF decreased as follows: alpha-methylstyrene > 4-methylstyrene > styrene and 1-methyl-1-cyclohexene > 1-phenyl-1-cyclohexene > cyclohexene. The catalyst could be recycled without detectable loss of efficiency.
Original language | English |
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Pages (from-to) | 151-158 |
Number of pages | 8 |
Journal | Advanced Synthesis & Catalysis |
Volume | 348 |
DOIs | |
Publication status | Published - 2006 |
Keywords
- asymmetric epoxidation
- chiral salen-manganese(III)
- heterogeneous catalysis
- immobilization
- LDH host catalyst
- HETEROGENEOUS ENANTIOSELECTIVE CATALYST
- HYDROXIDE-HOSTED CATALYSTS
- LAYERED DOUBLE HYDROXIDES
- MG-AL HYDROTALCITE
- NONFUNCTIONALIZED ALKENES
- UNFUNCTIONALISED OLEFINS
- MOLECULAR-OXYGEN
- COMPLEXES
- MCM-41
- CONVERSION