Title
Metathesis‐Based Stapling of a Pyridine−Acetylene−Phenol Oligomers Having Alkenyl Side Chains after Intermolecular Templation by Native Saccharides
Author
Hajime Abe, Chihiro Sato, Yuki Ohishi, Masahiko Inouye
Year
2018
Journal
European Journal of Organic Chemistry
Abstract
A nonameric (pyridine−acetylene−phenol−acetylene)4 −pyridine oligomer formed a helical structure by intermolecular templation with hexose such as D‐glucose associated by the means of solid‐liquid extraction. Consequently, treatment of Grubbs 2nd catalyst stapled the helix by double‐cross‐linking among four 3‐butenyloxy side chains on the pyridine units. The stapling never proceeded without the templation. The resulting double‐bridged helix could be asymmetrized to show typical Cotton effects, not only by the strong binding with octyl hexosides in a DCE solution but also by the solid‐liquid extraction of native hexoses into an organic phase. A chiral memory effect of the double‐bridged helix was studied by the guest exchange using equimolar D‐ and L‐glucosides, and half‐time of racemization of the helix was estimated to be 1 min.
Instrument
J-810
Keywords
Circular dichroism, Induced circular dichroism, Stereochemistry, Chemical stability, Kinetics, Ligand binding, Organic chemistry