Enantioselective conjugate addition of diethylzinc to chalcones catalysed by chiral Ni(II) aminoalcohol complexes
作者:André H.M. de Vries、Johan F.G.A. Jansen、Ben L. Feringa
DOI:10.1016/s0040-4020(01)89380-7
日期:1994.4
Conjugate addition of diethylzinc to chalcones is catalysed by complexes prepared in situ from Ni(acac)(2) and cis-exo-N,N-dialkyl-3-aminoisoborneols or (+)-cis-endo-N,N-dimethyl-3-aminoborneol ((+)- DAB) (13b). The products are obtained with enantioselectivities up to 84 %. When scalemic (-)-cis-exo-N,N-dimethyl-3-aminoisoborneol ((-)-DAIB) (3c) was employed in the reaction a positive nonlinear relationship was found. Several factors which govern catalyst activity and enantioselectivity have been investigated.