Exploration and Optimization of a Rotaxane Synthesis via Ring-Opening Cross Metathesis of a Catenane and a Doubly-Stoppered Axle
In our efforts to develop a new route toward rotaxane synthesis, we have envisioned the insertion method. This rotaxane-forming transformation can be achieved by the ring-opening of a catenane followed by its in situ “insertion” into a doubly-stoppered axle. The process incorporates two modern synthetic techniques, i.e. olefin metathesis and metal templation. The first step to study and optimize the insertion method is to synthesize three complex molecules i.e., a macrocycle, an α,ω-diene, and a doubly-stoppered axle. Our progress thus far includes the complete synthesis of both the macrocycle and the α,ω-diene, as well as the partial synthesis of the doubly-stoppered axle. Future work will include: (1) completing the synthesis of the doublystoppered axle via a cross-metathesis reaction, (2) synthesizing more α,ω-diene, (3) completing the synthesis of the catenane via complexation followed by olefin metathesis, and finally, (4) optimizing the insertion method.