title: Selective transformation of a crown ether/sec-ammonium salt-type rotaxane to N-alkylated rotaxanes.
abstract: Versatile functionalization of a crown ether/sec-ammonium salt-type rotaxane was accomplished. The rotaxane underwent reductive N-alkylation with sodium tri(acyloxy)borohydride or sodium tri(acyloxy)borohydride/arbitrary aldehyde in excellent yields. Structural switching based on reversible tert-ammonium/tert-amine conversion by acid and base was demonstrated as a pH-controlled molecular shuttle.
authors.affiliation: Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro-ku, Tokyo 152-8552, Japan.
authors.forename: Sakiko
authors.initials: S
authors.lastname: Suzuki
authors.forename: Kazuko
authors.initials: K
authors.lastname: Nakazono
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Takata