title: Powerful amino diol catalyst for effecting the direct asymmetric conjugate addition of aldehydes to acrylates.
abstract: Di-tert-butyl methylenemalonate (1) could be employed as a reactive equivalent of a three-carbon Michael acceptor such as acrylate in a direct asymmetric conjugate addition of aldehydes catalyzed by an axially chiral amino diol (S)-3a. Furthermore, acrylate, an unexplored and challenging substrate in enamine catalysis, has also been successfully employed in asymmetric conjugate addition reaction. Relatively inert acrylate is doubly activated by polyfluoroalkyl group of 2 and the hydroxyl group on the axially chiral amino diol catalyst (S)-3b, giving corresponding conjugate adducts in high yield with excellent enantiomeric excess. The obtained conjugate addition products were readily converted to synthetically useful and important chiral building blocks.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan.
authors.forename: Taichi
authors.initials: T
authors.lastname: Kano
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Shirozu
authors.forename: Matsujiro
authors.initials: M
authors.lastname: Akakura
authors.forename: Keiji
authors.initials: K
authors.lastname: Maruoka