Synthesis of C<sub>60</sub>/[10]CPP‐Catenanes by Regioselective, Nanocapsule‐Templated Bingel Bis‐Addition
Fabian M. Steudel, Ernest Ubasart, Luigi Leanza, Míriam Pujals, Teodor Parella, Giovanni M. Pavan, Xavi Ribas, Max von Delius
Abstract
Abstract The addition of two unsymmetric malonate esters to the Buckminster fullerene C 60 can lead to 22 spectroscopically distinguishable isomeric products and therefore represents a formidable synthesis challenge. In this work, we achieve 87 % selectivity for the formation of a single ( in , out ‐ trans ‐3) isomer by combining three approaches: (i) we use a starting material, in which the two malonates are covalently connected (tether approach); (ii) we form the strong supramolecular complex of C 60 with the shape‐persistent [10]CPP macrocycle (template approach) and (iii) we embed this complex further within a self‐assembled nanocapsule (shadow mask approach). Variation of the spacer chain shed light on the limitations of the approach and the ring dynamics in the unusual [2]catenanes were studied in silico with atomistic resolution. This work significantly widens the scope of mechanically interlocked architectures comprising cycloparaphenylenes (CPP).