New immobilized chiral Mn(III) salen complexes on pyridine N-oxide-modified MCM-41 as effective catalysts for epoxidation of nonfunctionalized alkenesR I, Kureshy and Irshad , Ahmed and N H, Khan and S.H.R., Abdi and Surendra, Singh and Preti H, Pandia and R V , Jasra (2005) New immobilized chiral Mn(III) salen complexes on pyridine N-oxide-modified MCM-41 as effective catalysts for epoxidation of nonfunctionalized alkenes. Journal of Catalysis , 235 (1). pp. 28-34.
AbstractWe prepared new chiral Mn(III) salen complexes 1′–4′ immobilized on pyridine N-oxide-modified MCM-41 through the axial coordination. Epoxidation of styrene and 4-chlorostyrene with the use of these complexes as catalysts in the presence of NaOCl was found to proceed enantioselectively (ee, 62–69%) at 0 °C in 8–12 h, which is a significantly higher enantioselectivity than that observed for their homogeneous counterparts (ee, 36–51%). These catalysts were also effective for the relatively bulkier alkenes, such as indene and 2,2-dimethylchromene, and have shown a reactivity (82–98%) and an enantioselectivity (69–92%) similar to those observed for their homogeneous system. The catalysts could be recycled several times without loss of performance.
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