Carbodiimide‐Induced Formation of Transient Polyether Cages**

The use of “fuel” compounds to drive chemical systems out equilibrium is currently interest because the potential for temporally controlled, responsive behavior. We have recently shown that transiently formed crown ethers exhibit counterintuitive templation effects when generated in presence alkali metal cations: “matched” cations, such as K+ with an 18-crown-6 analogue, suppress formation macrocycles (negative templation). In this work, we describe two macrocyclic diacids that, on treatment carbodiimides, give transient macrobicyclic cages analogous polyether cages. Negative are observed smaller cage and Na+, but there a weak, reproducible, positive effect Li+. larger behaves similarly Li+, K+, Rb+, Cs+, differently which appears bind both initial macrocycle.