Improbable Rotaxanes Constructed From Surrogate Malonate Rotaxanes as Encircled Methylene Synthons

Abstract We have developed a new approach for the synthesis of “improbable” rotaxanes by using malonate‐centered rotaxanes as interlocked surrogate precursors. Here, the desired dumbbell‐shaped structure can be assembled from two different, completely separate, portions, with the only residual structure introduced from the malonate surrogate being a methylene group. We have synthesized improbable [2]‐ and [3]rotaxanes with all‐hydrocarbon dumbbell‐shaped components to demonstrate the potential structural flexibility and scope of the guest species that can be interlocked when using this approach.