Asymmetric cyclopropanation catalyzed by Cu(I) complexes of new chiral pyridine containing macrocyclic ligands

The synthesis and characterisation of copper(I) complexes including two crystal structures of the new chiral pyridine-containing macrocyclic ligands (PC-type) and their use as catalysts in asymmetric cyclopropanation reactions are reported. The pyridine-based 12 membered tetraaza macrocyclic (PC-L*) ligands can be obtained in good overall yield (70-80%), starting from commercially available chiral aryl amines.1 The Cu(I) complexes of those ligands showed good catalytic activities in the cyclopropanation of differently substituted olefins employing ethyl diazoacetate (EDA) as carbene precursor.