title: Rational design of highly effective asymmetric Diels-Alder catalysts bearing 4,4'-sulfonamidomethyl groups.
abstract: The rational design of bis(oxazoline)-copper(II) catalysts based on postulated intramolecular secondary n-cation interaction for the highly enantioselective Diels-Alder reaction is presented. A theoretical calculation suggested that the n electrons of the 4,4'-sulfonamidomethyl groups successfully interact with the Cu(II) cation and that the counteranions with protons of sulfonamido groups. These secondary interactions might be essential for the high catalytic activity, the broad range of substrates, and the high level of induction of the enantioselectivity.
authors.affiliation: EcoTopia Science Institute, Graduate School of Engineering and JST, CREST, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8603, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Sakakura
authors.forename: Rei
authors.initials: R
authors.lastname: Kondo
authors.forename: Yuki
authors.initials: Y
authors.lastname: Matsumura
authors.forename: Matsujiro
authors.initials: M
authors.lastname: Akakura
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Ishihara