| Abstract
| - Chiral bis(oxazolines) are readily dialkylated in the methylene bridge, opening the way toimmobilization at that position, keeping the C2 symmetry of the chiral ligand. Bis(oxazolines)functionalized with two allyl or vinylbenzyl groups are easily grafted onto mercaptopropylsilica.Another approach to immobilization is the polymerization of the ligands bearing vinylbenzyl groupsto yield insoluble polymers. The Cu(OTf)2 complexes of the immobilized ligands promote theenantioselective cyclopropanation reaction between styrene and ethyl diazoacetate. The resultsdepend on the nature of the support and the method of immobilization. With regard to the type ofsolid, the best results, which are similar to or even better than those obtained with the correspondingdibenzylated homogeneous catalysts, are obtained with homopolymers. With regard to the bis(oxazoline), that bearing indan groups leads to good results both onto silica and polymers, whereaswith the ligand bearing tert-butyl groups good enantioselectivities are only obtained withhomopolymeric catalysts. Some of the heterogeneous catalysts can be easily recovered and reused,as much as five times, with the same yield and stereoselectivities.
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