Novel chiral sulphonato-salen-manganese (III)-pillared hydrotalcite catalysts for the asymmetric epoxidation of styrenes and cyclic alkenes

S Bhattacharjee, J A Anderson

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46 Citations (Scopus)

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 languageEnglish
Pages (from-to)151-158
Number of pages8
JournalAdvanced Synthesis & Catalysis
Volume348
DOIs
Publication statusPublished - 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

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