title: Nickel(II)-catalyzed asymmetric propargyl and allyl Claisen rearrangements to allenyl- and allyl-substituted β-ketoesters.
abstract: Highly efficient catalytic asymmetric Claisen rearrangements of O-propargyl β-ketoesters and O-allyl β-ketoesters have been accomplished under mild reaction conditions. In the presence of the chiral N,N'-dioxide/Ni(II) complex, a wide range of allenyl/allyl-substituted all-carbon quaternary β-ketoesters was obtained in generally good yield (up to 99%) and high diastereoselectivity (up to 99:1 d.r.) with excellent enantioselectivity (up to 99% ee).
authors.affiliation: Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064 (China).
authors.forename: Yangbin
authors.initials: Y
authors.lastname: Liu
authors.forename: Haipeng
authors.initials: H
authors.lastname: Hu
authors.forename: Haifeng
authors.initials: H
authors.lastname: Zheng
authors.forename: Yong
authors.initials: Y
authors.lastname: Xia
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: allenic compounds; asymmetric catalysis; heterocycles; nickel; rearrangement