Improvement of the performance of interlocked compounds by the selective modification of their structure

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Secondary ammonium salts having cinnamyl alcohol moiety at the termini were prepared. Corresponding pseudorotaxanes were prepared with 24-membered crown ether. The end-capping reaction was carried out by the acylation reaction catalyzed by tributylphosphane to afford rotaxanes having bulky cinnamyl ester group at the termini. The reaction of thus obtained rotaxanes with bulky allylmalonate ester catalyzed by the palladium complexes was investigated using dppp as the bulky ligand. The new rotaxanes having malonate group was obtained in good yield. The yield increased as the amount of the palladium catalyst decreased. When 5 mol% of the catalyst was used, 95% of end-cap-exchange was achieved. Although the ammonium group in the rotaxane did not disturb the reaction, the reaction was strongly suppressed by the steric hindrance of the crown ether. The reaction proceeded without the destruction of the interlocked structure because the axle component could not thread out from the axle due to … More the bulky dppp ligand on the palladium catalyst during the palladium complex activated the terminal cinnamate ester group. Further, a rotaxane having sulfolene moiety that is the masked 1,3-diene was prepared using the hydrogen-bonding interaction between amide groups. When this rotaxane was heated in the presence of dienophile such as fumalate ester, the decomposition of sulfolene moiety followed by the Diesl-Alder reaction simultaneously occurred to afford a new rotaxane having cyclohexene group. Ozone oxidation of thus obtained rotaxane afforded the rotaxane in which the axle component was elongated by the cleavage of the carbon-carbon double bond. A catenane comprising sulfolene-containing ring and fumalate ester-containing ring was similarly prepared using the hydrogen-bonding interaction between amide groups. Upon heating the catenane, a polycatenane having bridged polycatenane structure by the Diels-Alder polymerization. Although this polymer has bridged structure, this is the first example of the polymer having polycatenane skeleton. Less