Biomimetic Catalysis of an SN2 Reaction Resulting from a Novel Form of Transition‐State Stabilization

A cation – π-electron interaction is the essential factor responsible for the stabilization of the transition state during the methylation of quinoline (and related bases) with methyl iodide by a cage host compound (see picture on the right). The stabilization results in a catalytic effect: In the presence of the host the reaction is accelerated by a factor of 100. The system provides a primitive model for enzymatic methylation.