Expanding the Pillararene Chemistry: Synthesis and Application of a 10 + 1 Functionalized Pillar[5]arene

A novel functionality was introduced in the pillararene family by the Claisen rearrangement of monoallyl pillar[5]­arene. This new key derivative can lead to the formation of a 10 + 1 functionalized derivative, a useful scaffold for further derivatization. Except for the previously known monodeprotection reaction, all steps proceed efficiently with high yields and easy separation. In addition, a solvent-responsive pseudo[1]­rotaxane was synthesized based on this novel functionality.