Chiral C₂-symmetric α- and ω-diimines with bulky substituents at nitrogen: Synthesis and catalytic properties of some copper complexes

Two new C₂-symmetric chiral α- and ω-Diimines incorporating bulky ferrocenylethylamine and their copper(I) complexes have been synthesized and characterized by analytical and various spectroscopic techniques. The catalytic activities of these complexes, have been tested in the asymmetric cyclopropanation of a series of olefins with some diazoacetates to achieve varying degree of dia- and enantio-selectivities depending on the nature of the ligand, the substrates, and the reagents. Some mechanistic implication has been made with regard to the interactions among all these chemical species.