Single-step enantioselective synthesis of mechanically planar chiral [2]rotaxanes using a chiral leaving group strategy

DOI: 10.1021/jacs.0c03447

Authors: Chong Tian (University of Manchester) , Stephen D. P. Fielden (University of Manchester) , Borja Pérez-Saavedra (University of Manchester) , Iñigo J. Vitorica-Yrezabal (University of Manchester) , David Leigh (University of Manchester; East China Normal University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of The American Chemical Society

State: Published (Approved)
Published: May 2020

Abstract: We report a one-step enantioselective synthesis of mechanically planar chiral [2]rotaxanes. Previous studies of such molecules have generally involved the separation of enantiomers from racemic mixtures or the preparation and separation of diastereomeric intermediates followed by post-assembly modification to remove other sources of chirality. Here, we demonstrate a simple asymmetric metal-free active template rotaxane synthesis using a primary amine, an activated ester with a chiral leaving group, and an achiral crown ether lacking rotational symmetry. Mechanically planar chiral rotaxanes are obtained directly in up to 50% enantiomeric excess. The rotaxanes were characterized by NMR spectroscopy, high-resolution mass spectrometry, chiral HPLC, single crystal X-ray diffraction, and circular dichroism. Either rotaxane enantiomer could be prepared selectively by incorporating pseudoenantiomeric cinchona alkaloids into the chiral leaving group.

Subject Areas: Chemistry


Instruments: I19-Small Molecule Single Crystal Diffraction

Added On: 14/05/2020 09:46

Documents:
jacs.0c03447.pdf

Discipline Tags:

Chemistry Organic Chemistry

Technical Tags:

Diffraction Single Crystal X-ray Diffraction (SXRD)