Asymmetric Copper-Catalyzed Cyclopropanation of Trisubstituted and Unsymmetrical cis-1,2-Disubstituted Olefins: Modified Bis-Oxazoline Ligands

Article abstract of DOI:10.1016/0040-4039(91)80110-R

The Cu(I) complexes of new bis-oxazolines (3-7) prepared from the corresponding amino alcohols and malono-bis-imidate exhibit high enantioselectivity of up to 94 percent ee in the catalytic cyclopropanation of trisubstituted and unsymmetrical cis-1,2-disubstituted olefins.New diazoacetate reagents have also been developed giving high trans/cis ratios of up to 99:1 trans.