title: Homochiral [2]Catenane and Bis[2]catenane from Alleno-Acetylenic Helicates - A Highly Selective Narcissistic Self-Sorting Process.
abstract: Homochiral strands of alternating alleno-acetylenes and phenanthroline ligands (P)-1 and (P2)-2, as well as their corresponding enantiomers, selectively assemble with the addition of silver(I) salt to yield dinuclear and trinuclear double helicates, respectively. Upon increasing the solvent polarity, the dinuclear and trinuclear helicates interlock to form a [2]catenane and bis[2]catenane, bearing 14 chirality elements, respectively. The solid-state structure of the [2]catenane reveals a nearly perfect fit of the interlocked strands, and the ECD spectra show a significant amplification of the chiroptical properties upon catenation, indicating stabilization of the helical secondary structure. Highly selective narcissistic self-sorting was demonstrated for a racemic mixture consisting of both short and long alleno-acetylenic strands, highlighting their potential for the preparation of linear catenanes of higher order.
authors.affiliation: Laboratory of Organic Chemistry, ETH Zurich , Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland.
authors.forename: Ori
authors.initials: O
authors.lastname: Gidron
authors.affiliation: Laboratory of Organic Chemistry, ETH Zurich , Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Jirásek
authors.affiliation: Laboratory of Organic Chemistry, ETH Zurich , Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland.
authors.forename: Nils
authors.initials: N
authors.lastname: Trapp
authors.affiliation: Laboratory of Organic Chemistry, ETH Zurich , Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland.
authors.forename: Marc-Olivier
authors.initials: MO
authors.lastname: Ebert
authors.affiliation: Laboratory of Organic Chemistry, ETH Zurich , Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Laboratory of Organic Chemistry, ETH Zurich , Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland.
authors.forename: François
authors.initials: F
authors.lastname: Diederich