共有結合を経由するロタキサンの合成とその機能

概要

論文の詳細を見る
Crownophanes which were used as rotor molecules in this review were prepared via tandem Claisen rearrangement (TCR). Primary amines having a bulky end group were also prepared to use as a part of axle molecules. Using crownophanes, a new method to prepare rotaxane systems has been developed. That is, we call it “a method via covalent bond formation”. This method contains two processes, esterification and aminolysis. The first step is the reaction of hydroxy group of macrocyclic compounds (crownophanes) with acid chloride, and the second step is the reaction of the ester produced with amine having a bulky end group. This method successfully gave [1]-, [2]-, and [3]rotaxanes in moderate yields. In the fluorescence spectrum, the efficient energy transfer from rotor molecules to end anthryl group of axle molecules was observed in the [n]rotaxanes. In the presence of lithium ion, the energy transfer occurred very efficiently, but not in the presence of other ions. Chiral recognition for phenylalaninol was also observed using achiral rotaxane having asymmetrical rotor and axle. We also reported that our rotaxanes could attach on the gold surface. We successfully observed the single rotaxanes by atomic force microscope. Thus, we report here that the rotaxane synthesis via covalent bond formation is successfully performed to give many kinds of rotaxanes starting from crownophanes which were prepared via TCR.