Pillar[5]arene-Based [2]Rotaxane: Synthesis, Characterization, and Application in a Coupling Reaction

Mechanically interlocked molecules are a class of smart supramolecular species because of their interesting topological structure and application in various areas, such as biology and nanoscience. In this work, we used “multicomponent reaction” to fabricate a new [2]­rotaxane based on pillar[5]­arene from different small-sized molecules. The molecular structure of the obtained [2]­rotaxane R was confirmed by 1H and 13C NMR, high-resolution electrospray ionization mass spectrometry, two-dimensional nuclear Overhauser effect spectroscopy, and density functional theory studies. Interestingly, the [2]­rotaxane-based organometallic cross-linked catalyst (Pd@R) was easily constructed via the coordination between triazole groups and Pd­(NO3)2. Pd@R proved to be a good catalyst for the Suzuki–Miyaura coupling reaction with excellent stability and repeatability.