title: Scandium-catalyzed asymmetric 1,6-addition of 3-substituted oxindoles to linear dienyl ketones.
abstract: The first example of a N,N'-dioxide-Sc(III) -catalyzed 1,6-addition of 3-substituted oxindoles to dienyl ketones has been developed. This procedure tolerates a relatively wide range of 3-substituted oxindoles under mild conditions, facilitating the preparation of various chiral oxindoles with quaternary stereocenters. In addition, the reliable catalyst was found to be effective in the asymmetric 1,6-addition of both δ-unsubstituted and δ-methyl-substituted dienyl ketones, achieving excellent regioselectivities and enantioselectivities (up to>99 % ee).
authors.affiliation: Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064 (P. R. China), Fax: (+86) 28-8541-8249.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.forename: Tengfei
authors.initials: T
authors.lastname: Kang
authors.forename: Qian
authors.initials: Q
authors.lastname: Yao
authors.forename: Jie
authors.initials: J
authors.lastname: Ji
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Liu
authors.forename: Lili
authors.initials: L
authors.lastname: Lin
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Feng
keywords: 1,6-addition reaction; N,N′-dioxides; asymmetric catalysis; diastereoselectivity; scandium