Polymer-supported Bis(oxazoline)-copper complexes as catalysts in cyclopropanation reactions
Bis(oxazolines) are easily immobilized by functionalization of the central methylene bridge with polymerizable groups and subsequent polymerization. Polymers are transformed into copper catalysts active in the cyclopropanation of styrene with ethyl diazoacetate. The results are similar or even better than those obtained with the similar homogeneous systems, and the catalysts can be easily recovered and reused. The substitution in the methylene bridge leads to a slight reduction in the enantioselectivity and an unexpected cis-preference.
Burguete
MI
Departamento de Quimica Inorganica y Organica, E.S.T.C.E., Universidad Jaume I, E-12080 Castellon, and Departamento de Quimica Organica, Instituto de Ciencia de Materiales de Aragon, Facultad de Ciencias, Universidad de Zaragoza-
Fraile
JM
Garcia
JI
Garcia-Verdugo
E
Luis
SV
Mayoral
JA