A new insoluble polymer-bound bisoxazoline (IPB-box) was prepared by grafting a suitable chiral ligand derivative onto a commercial Merrifield resin. The material obtained by this route was employed in the asymmetric copper-catalyzed olefin cyclopropa nation, obtaining good activity and enantioselectivity values (54-84% yield, 71-93% ee) for a range of substrates. In addition, some key factors required for the development of effective IPB-box systems are discussed, including the local ligand symmetry and the influence of immobilization technique and catalyst loading.
Some factor affecting the catalytic efficiency in the enantioselective cyclopropanation of olefins by the use of insoluble polystyrene-bound bisoxazoline-copper(I) complex
MANDOLI, ALESSANDRO;PINI, DARIO;LESSI, MARCO;SALVADORI, PIERO
2009-01-01
Abstract
A new insoluble polymer-bound bisoxazoline (IPB-box) was prepared by grafting a suitable chiral ligand derivative onto a commercial Merrifield resin. The material obtained by this route was employed in the asymmetric copper-catalyzed olefin cyclopropa nation, obtaining good activity and enantioselectivity values (54-84% yield, 71-93% ee) for a range of substrates. In addition, some key factors required for the development of effective IPB-box systems are discussed, including the local ligand symmetry and the influence of immobilization technique and catalyst loading.File in questo prodotto:
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