A chiral menthyl cyclopentadienyl molybdenum tricarbonyl chloro complex:: Synthesis, heterogenization on MCM-41/MCM-48 and application in olefin epoxidation catalysis

The complex [(-)-menthylCp]MO(CO)(3)Cl (1) was synthesized by the reaction of MO(CO)(3)(EtCN)(3) with [(-)-menthvlCpH] to produce the hydride [(-)-menthylCp]Mo(CO)(3)H. The latter compound was then reacted with CCl4 to form [(-)-menthylCp]MO(CO)(3)Cl (1). Compound I was tested as catalyst for the epoxidation of cis-cyclooctene, styrene and traits-beta-methyl styrene in the presence of tert-butyl hydroperoxide (TBHP) at 55 degrees C using chloroform as solvent. Results under homogeneous conditions prompted the authors to immobilize complex 1 on mesoporous MCM-41 and MCM-48 surfaces leading to the grafted materials AM-41CpMoChi and AM-48CpMoChi. The presence of the organometallic complexes in the materials was confirmed by powder X-ray diffraction, N-2 adsorption/desorption isotherms, TEM, EA, FT-IR, H-1 MAS NMR and TG-MS. AM-41CpMoChi and AM-48CpMoChi were also tested as epoxidation catalysts. The catalytic examinations also included leaching experiments, and the reusing of the grafted materials for several runs. (c) 2006 Elsevier B.V. All rights reserved.