A series of ruthenium complexes incorporating ″salen-type″ Schiff-base ligands were prepared and used for alkene cyclopropanation with high trans/cis ratio and high enantioselectivity. Solution NMR and XRD studies show that depending on the ligand characteristic, the metal complex adopts a cis or trans coordination mode, reflecting the catalytic activity in the cyclopropanation reaction. The presence of a potential catalytic intermediate, a metallocarbene species, in solution state was determined. Effects of ligand substituent on the diastereo- and enantioselective cyclopropanation was discussed. Original is an abstract.
ASJC Scopus subject areas
- Chemical Engineering(all)