Dynamic Control of Chiral Space Through Local Symmetry Breaking in a Rotaxane Organocatalyst

Research output: Contribution to journalArticle

  • Authors:
  • Marcel Dommaschk
  • Javier Echavarren
  • David Leigh
  • Vanesa Marcos
  • Thomas A Singleton

Abstract

We report on a switchable rotaxane molecular shuttle that features a pseudo‐meso 2,5‐disubstituted pyrrolidine catalytic unit on the axle whose local symmetry is broken according to the position of a threaded benzylic amide macrocycle. The macrocycle can be selectively switched (with light in one direction; with catalytic acid in the other) with high fidelity between binding sites located to either side of the pyrrolidine unit. The position of the macrocycle dictates the facial bias of the rotaxane‐catalyzed conjugate addition of aldehydes to vinyl sulfones. The pseudo‐meso non‐interlocked thread does not afford significant selectivity as a catalyst (2‐14% ee), whereas the rotaxane affords selectivities of up to 40% ee with switching of the position of the macrocycle changing the handedness of the product formed (up to 60% Δee).

Bibliographical metadata

Original languageEnglish
JournalAngewandte Chemie International Edition
Early online date27 Aug 2019
DOIs
Publication statusPublished - 2019