1032277-62-5Relevant academic research and scientific papers
Rational Design for Rotaxane Synthesis through Intramolecular Slippage: Control of Activation Energy by Rigid Axle Length
Masai, Hiroshi,Terao, Jun,Fujihara, Tetsuaki,Tsuji, Yasushi
, p. 6624 - 6630 (2016)
We describe a new concept for rotaxane synthesis through intramolecular slippage using π-conjugated molecules as rigid axles linked with organic soluble and flexible permethylated α-cyclodextrins (PM α-CDs) as macrocycles. Through hydrophilic-hydrophobic interactions and flipping of PM α-CDs, successful quantitative conversion into rotaxanes was achieved without covalent bond formation. The rotaxanes had high activation barrier for their de-threading, so that they were kinetically isolated and derivatized even under conditions unfavorable for maintaining the rotaxane structures. 1H NMR spectroscopy experiments clearly revealed that the restricted motion of the linked macrocycle with the rigid axle made it possible to control the kinetic stability by adjusting the length of the rigid axle in the precursor structure rather than the steric bulkiness of the stopper unit.
Synthesis of linked symmetric [3]rotaxane having an oligomeric phenylene-ethynylene unit as a π guest via double Sonogashira cross-coupling
Terao, Jun,Wadahama, Akihisa,Fujihara, Tetsuaki,Tsuji, Yasushi
, p. 518 - 519 (2010)
Linked symmetric [3]rotaxanes consisting of an oligomeric phenylene-ethynylene (OPE) unit as a π-conjugated guest and two molecules of organic soluble permethylated a-cyclodextrins (PM CDs) as macrocyclic hosts have been synthesized by intramolecular self-inclusion of an OPE guest moiety carrying PM a-CDs followed by double cross-coupling reaction with 1,4diiodobenzene under the Sonogashira coupling conditions. The structure of thus formed rotaxane was determined by MALDITOF mass spectrum and two-dimensional NMR spectroscopy.
