6533b820fe1ef96bd1279891

RESEARCH PRODUCT

Immobilized Chiral ortho-Metalated Dirhodium(II) Compounds as Catalysts in the Asymmetric Cyclopropanation of Styrene with Ethyl Diazoacetate

Klaus BiegerJulio LloretAnd Cristina VillanuevaFrancisco EstevanMa Angeles ÚBeda

subject

chemistry.chemical_classificationCyclopropanationOrganic ChemistryDiastereomerPolymerStyreneCatalysisInorganic Chemistrychemistry.chemical_compoundchemistryEthyl diazoacetateHomogeneousPolymer chemistryOrganic chemistryCarboxylatePhysical and Theoretical Chemistry

description

Immobilization of ortho-metalated dirhodium(II) compounds has been achieved by a carboxylate interchange reaction between (M)-Rh2(l-protos)2[(p-XC6H3)P(p-XC6H4)2]2 diastereoisomers and carboxyethylpolystyrene polymer (PS-C6H4(CH2)2CO2H). The immobilized chiral catalysts have been tested in the standard reaction of asymmetric cyclopropanation of styrene with ethyl diazoacetate, giving higher yields than homogeneous chiral trifluoroacetate derivatives, but their diastereo- and enantioselectivities were lower. Some of the immobilized catalysts have proved to be very robust. The catalytic behavior of (M)-Rh2(O2C(CH2)2C6H5)2[(p-XC6H3)P(p-XC6H5)2]2 compounds has been studied as a model for the immobilized catalysts.

yearjournalcountryeditionlanguage
2007-07-21Organometallics
https://doi.org/10.1021/om061086t