LAUSR

The elucidation of the requirements for efficient catalysis within supramolecular host systems is an important prerequisite for developing novel supramolecular catalysts. The resorcinarene hexamer has recently been shown to be the first supra-molecular catalyst to promote the tail-to-head terpene cyclization in a biomimetic fashion. We herein present the synthesis of a number of resorcinarene-based macrocycles capable of self-assembly, and compare the corresponding assemblies regarding their catalytic activity in the cyclization of monoterpenes. The assemblies were investigated in detail with respect to a number of properties including the encapsulation of substrate, and ion pairs, the structural incorporation of water and the response to externally added acid (HCl). The results obtained strongly indicate that water incorporated into the hydrogen bond network of the self-assembled structure plays an integral role for catalysis, effectively acting as a proton shuttle to activate the encapsulated substrate. These findings are also supported by molecular dynamics simulations, providing further insight into the protonation pathway and the relative energies of the intermediates involved.