Chiral ansa-bridged η5-cyclopentadienyl molybdenum complexes: Synthesis, structure and application in asymmetric olefin epoxidation

Ansa-bridged η5-cyclopentadienyl carbonyl molybdenum complexes were synthesized with stereogenic centers located in the side chain. An exemplary X-ray crystal structure and the catalytic activity for asymmetric olefin epoxidation are reported. In non-chiral epoxidation the compounds show a good catalytic activity, comparable to activities observed for the related non-chiral complexes of composition CpMo(CO)3X (X = Cl, CH3). For the asymmetric epoxidation of trans-β-methylstyrene the chiral induction is up to ca. 20%. The high ring strain of the ansa-bridged system hampers, unfortunately, its stability under oxidative condition.

Graphical abstractAnsa-bridged η5-cyclopentadienyl carbonyl molybdenum complexes were synthesized with stereogenic centers located in the side chain. The compounds show a good catalytic activity, comparable to activities observed for the related non-chiral complexes of composition CpMo(CO)3X (X = Cl, CH3). The high ring strain of the ansa-bridged system hampers, unfortunately, its stability under oxidative condition.Figure optionsDownload full-size imageDownload as PowerPoint slide