The copper-catalyzed enantioselectiveconjugateaddition of diethylzinc to acyclic enones was achieved with chiral sulfoxide–phosphine (SOP) ligands. This process showed good functional group tolerance and gave the 1, 4-adducts with excellent enantioselectivities (up to 96% ee).
optically active molecules. Procedures that employ chiral homogeneous catalysts have been developed extensively, but ones that use chiral heterogeneouscatalysts are less explored and remain a challenge. Here we report a polymer-supported chiral heterogeneous copper catalyst that demonstrated high reactivity and enantioselectivity in asymmetric conjugate addition reactions of both ketones and imines. It was
Chiral dinuclear phthalazine bridged bisoxazoline ligands: synthesis and application in enantioselective Cu-catalyzed conjugate addition of ZnEt2 to enones
A new class of chiral dinuclear ligands with phthalazine bridged bisoxazoline scaffold was designed and prepared in convenient synthetic routes. H-1 NMR analysis showed that this class of ligands could coordinate with two metal ions, either same or different. These ligands afforded good to excellent yields and enantioselectivities in Cu-catalyzed conjugate addition of ZnEt2 to enones. (C) 2011 Elsevier Ltd. All rights reserved.
Modulation of Multifunctional N,O,P Ligands for Enantioselective Copper-Catalyzed Conjugate Addition of Diethylzinc and Trapping of the Zinc Enolate
chiral primary amine. The controllable synthesis of a novel hexadentate and tetradentate N,O,P ligand that contains both axial and sp3‐central chirality from axial BINOL and sp3‐central primary amine led to the establishment of an efficient multifunctional N,O,P ligand for copper‐catalyzed conjugate addition of an organozinc reagent. In the asymmetric conjugate reaction of organozinc reagents to enones,