Challenges and Opportunities in the Post‐Synthetic Modification of Interlocked Molecules

Several strategies have been successfully utilized so far in order to obtain a wide range of interlocked molecules. However, some interlocked compounds are still not obtained directly and/or efficiently from non-interlocked components because the requisites for self-assembly cannot be always enforced. To circumvent such a synthetic problem, the strategy that consists in synthesizing an isolable and storable interlocked building block in a step that precedes its modifications is an appealing chemical route to more sophisticated interlocked molecules. Synthetic opportunities and challenges are closely linked to the fact that the mechanical bond might tremendously affect the reactivity of a function of the encircled axle, while the interlocked architecture need to be preserved during the synthesis. Hence, the mechanical bond plays a fundamental role in the strategy employed. This review focuses on the challenging post-synthetic modifications of interlocked molecules, sometimes through the cleavage of the axle's main chain, and always with the conservation of the mechanical bond.