title: Enantioselective C-H carbene insertions with homogeneous and immobilized copper complexes.
abstract: The efficiency of chiral bis(oxazoline)- and azabis(oxazoline)-copper complexes in the enantioselective carbene insertion into C-H bonds of cyclic ethers in homogeneous phase strongly depends on the structure of the substrate. The immobilization on laponite clay by electrostatic interactions not only allows the recovery and reuse of the heterogeneous catalysts, but in some cases also improves enantioselectivity and overall chemoselectivity, making possible reactions that do not take place or lead to low yields in solution, even with the commonly used Rh(2)[S-DOSP](4) catalyst.
authors.affiliation: Departamento de Química Orgánica, Instituto de Ciencia de Materiales de Aragón, Facultad de Ciencias, Universidad de Zaragoza-C.S.I.C., E-50009, Zaragoza, Spain. jmfraile@unizar.es
authors.forename: José M
authors.initials: JM
authors.lastname: Fraile
authors.forename: Pilar
authors.initials: P
authors.lastname: López-Ram-de-Viu
authors.forename: José A
authors.initials: JA
authors.lastname: Mayoral
authors.forename: Marta
authors.initials: M
authors.lastname: Roldán
authors.forename: Jorge
authors.initials: J
authors.lastname: Santafé-Valero