title: Kinetic resolution of acyclic secondary allylic silyl ethers catalyzed by chiral ketones.
abstract: Kinetic resolution of acyclic secondary allylic silyl ethers by chiral dioxiranes generated in situ from chiral ketones (R)-1 and (R)-2 and Oxone was investigated. An efficient and catalytic method has been developed for kinetic resolution of those substrates with a CCl(3), tert-butyl, or CF(3) group at the alpha-position. In particular, high selectivities (S up to 100) were observed for kinetic resolutions of racemic alpha-trichloromethyl allylic silyl ethers 7 and 9-15 catalyzed by ketones (R)-2. Both the recovered substrates and the resulting epoxides were obtained in high enantiomeric excess. On the basis of steric and electrostatic interactions between the chiral dioxiranes and the racemic substrates, a model was proposed to rationalize the enantioselectivities and diastereoselectivities in the chiral ketone-catalyzed kinetic resolution process.
authors: Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong. yangdan@hku.hk
authors: D
authors: D
authors: Yang
authors: G S
authors: GS
authors: Jiao
authors: Y C
authors: YC
authors: Yip
authors: T H
authors: TH
authors: Lai
authors: M K
authors: MK
authors: Wong