Polytopic Oxazoline‐Based Chiral Ligands for Cyclopropanation Reactions: A New Strategy to Prepare Highly Recyclable Catalysts

Zusammenfassung

New polytopic chiral copper complexes based on azabis(oxazoline) moieties have been synthesized and applied in cyclopropanation reactions of several alkenes. Excellent enantioselectivities have been obtained in all cases and additionally, the catalysts have been recovered in up to 14 cycles without noticeable loss of activity and selectivity. Analysis of the copper complexes by mass spectrometry suggests the formation of coordination polymers, representing the resting state of the catalysts.