Heterogeneous asymmetric Diels-Alder reactions using a copper-chiral bis(oxazoline) complex immobilized on mesoporous silica

Abstract

A chiral bis(oxazoline)-copper complex was immobilized onto mesoporous silica and the resulting heterogeneous catalyst was employed in asymmetric Diels-Alder reactions. Reactions using the catalyst exhibited good enantioselectivity of 78% enantiomeric excess and endo/exo-selectivity (17:1) better than the corresponding homogeneous reaction. The catalyst could be easily recovered and reused several times without significant loss of the remarkable reactivity, diastereoselectivity and enantioselectivity. (C) 2002 Published by Elsevier Science Ltd.