title: The effects of solvent on switchable stereoselectivity: copper-catalyzed asymmetric conjugate additions using D2-symmetric biphenyl phosphoramidite ligands.
abstract: A highly enantioselective copper-catalyzed conjugate addition of diethylzinc to acyclic aromatic enones was developed with phosphoramidite ligands bearing a D(2)-symmetric biphenyl backbone. This type of reaction demonstrated that toluene and THF solvents can completely reverse the absolute configuration of the products, thus simplifying the process of accessing either enantiomer (S: 92% ee, 94% yield; R: 99% ee, 96% yield).
authors.affiliation: School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P. R. China.
authors.forename: Han
authors.initials: H
authors.lastname: Yu
authors.forename: Fang
authors.initials: F
authors.lastname: Xie
authors.forename: Zhenni
authors.initials: Z
authors.lastname: Ma
authors.forename: Yangang
authors.initials: Y
authors.lastname: Liu
authors.forename: Wanbin
authors.initials: W
authors.lastname: Zhang