C2-symmetric Schiff bases derived from ñ-camphor and R-fenchone (1-6) were prepared, their configurational and conformational features determined by ID- and 2D-NMR spectra and supported by MM2 calculations. Their Cu(I) complexes prepared in situ were examined in cyclopropanation of styrene and low to medium e.e.\u27s (2-32%) were obtained. Correlation of the structure of E,E-1 and Z,Z-6 with enantioselectivity of their Cu(I) complexes revealed restricting steric requirements in the former, possessing gem dimethyl group in the proximity of the chiral centre, near to the coordination sphere of alkene and carbene, as the probable origin of its higher enantioselectivity
