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Updated: May 31, 2026

Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
Enantioselective C-H carbene insertions with homogeneous and immobilized copper complexes
José M Fraile1, Pilar López-Ram-de-Viu, José A Mayoral
1Departamento 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
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.
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