Helix‐Rotaxane Hybrid Systems: Rotaxane‐Stabilized, Saccharide‐Induced Chiral Ethynylpyridine Helices by a Thermodynamic Process. Issue 3 (24th January 2017)

• Record Type: Journal Article
• Authors: Hirokane, Shu; Takashima, Shunsuke; Abe, Hajime; Inouye, Masahiko
• Is Part Of: European journal of organic chemistry. Issue 3(2017)
• Page Start: 726
• Page End: 733
• Publication Date: 2017-01-24
• Subjects: Helical structures -- Rotaxanes -- Host–guest systems -- Molecular recognition -- Glycosides; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201601323
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract : The helical structures of m ‐ethynylpyridine (2, 6‐pyridyleneethynylene) oligomers have been stabilized by mechanical crosslinking. A heptameric oligomer, in which the two terminal pyridine rings bear two carbaldehyde groups, has been designed. When this heptamer was treated with octyl β‐d ‐glucopyranoside, a circular dichroism (CD) band was induced at around 330 nm, which corresponds to the formation of a chiral ethynylpyridine helix. The CD band was enhanced by the addition of a diamine and a diammonium dumbbell as a result of the formation of a [3]rotaxane structure linked to the terminal pyridines of the helical structure. A decameric oligomer containing four diformylarene units showed stronger CD enhancement in similar experiments owing to two crosslinking events. Abstract : The helical structure of m ‐ethynylpyridine oligomers is stabilized by the mechanical bonding of [3]rotaxane moieties to side‐chains in the oligomeric structure. The [3]rotaxane was constructed by a thermodynamic process and the handedness of the helix could be biased by glucoside recognition inside the helix.