Synthesis of Rotaxanes by Brief Melting-of Wheel and Axle Components

摘要

In 1995 we synthesized the first amide-type rotaxanes by forming the amide bond of the axle in the presence of the wheel. The triphenylmethyl stoppers used were sterically demanding enough to prevent wheels of type 1 from slipping off the axle. We have been searching for a way to thread such a rnacrocycle onto a preassembled axle by using a "slipping approach" analogous to that described previously for other types of rotaxanes. In the course of this research we have synthesized amide-type rotaxanes 2by simply melting the preassembled wheel and axle components for about one minute.