Selective synthesis of a [3]rotaxane consisting of size-complementary components and its stepwise deslippage.

An α-cyclodextrin-based size-complementary [3]rotaxane with an alkylene axle was selectively synthesized in one pot via an end-capping reaction with 2-bromophenyl isocyanate in water. Thermal degradation of the [3]rotaxane product yielded not only the original components but also the [2]rotaxane. Thermodynamic studies suggested a stepwise deslippage process.