Rotaxanation as a sequestering template to preclude incidental metal insertion in complex oligochromophores

The high yielding Cu^I-mediated click reaction is an effective procedure for the preparation of oligoporphyrinoid conjugates. However, the Cu^I 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 Cu^I-mediated click reactions with metal cation sequestration to avoid detrimental effects caused by the presence of copper cations.