Electrophilic Substitution of Deep Cavity Cavitands:  Selective Exo Functionalization of Molecular Concavity

The functionalization of deep-cavity cavitands via electrophilic substitution was investigated. In the parent structures, substitution occurs both at the exo position of the bowl-shaped hosts and on the convex face. Little or no endo substitution was observed. In contrast, derivatives in which methyl groups blocked the reaction sites on the convex face reacted selectively at the exo positions.