title: Iridium-catalyzed asymmetric [3+2] annulation of aromatic ketimines with alkynes via C-H activation: unexpected inversion of the enantioselectivity induced by protic acids.
abstract: A cationic iridium/binap catalyst enabled the asymmetric [3+2] annulation of cyclic N-acyl ketimines with internal alkynes via C-H activation to give spiroaminoindene derivatives with high enantioselectivity. The stereochemical course of this annulation was switchable by acid additives.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan. tnishi@kuchem.kyoto-u.ac.jp.
authors.forename: Midori
authors.initials: M
authors.lastname: Nagamoto
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yamauchi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nishimura