Rotaxanation as a sequestering template to preclude incidental metal insertion in complex oligochromophores†
The high yielding CuI-mediated click reaction is an effective procedure for the preparation of oligoporphyrinoid conjugates. However, the CuI catalyst leads to the adventitious and usually undesirable insertion of Cu ions into any non-metalated porphyrinoid centers during reaction. Here we report a “sacrificial rotaxane” strategy for the multifunctionalization of porphyrins with free base corroles without incidental copper insertion. This strategy can be considered a general method for implementing CuI-mediated click reactions with metal cation sequestration to avoid detrimental effects caused by the presence of copper cations.