title: Anti-Selective Asymmetric Nitro-Michael Reaction of Furanones: Diastereocontrol by Catalyst.
abstract: Catalyst-controlled switching of diastereoselectivity from high syn-selectivity (>98/2 dr, syn) to anti-selectivity (up to 96/4 dr, anti) of the asymmetric nitro-Michael reaction of furanones is described. Anti-diastereoselectivity of the nitro-Michael reaction is very rare. With 0.1-5 mol % loadings of an epi-quinine catalyst, the reaction of 5-substituted 2(3H)-furanones with nitroalkenes smoothly proceeded to give the anti-Michael adducts in good yields (up to 95%) with excellent diastereo- and enantioselectivities (up to 96/4 dr, anti; up to 99% ee). DFT calculations support a model that accounts the high anti-diastereoselectivity.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka City University , Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Sekikawa
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka City University , Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kitaguchi
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka City University , Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Kitaura
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka City University , Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Minami
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka City University , Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Hatanaka