Primary Anion-π Catalysis and Autocatalysis.

Epoxide-opening ether cyclizations are shown to occur on π-acidic aromatic surfaces without the need of additional activating groups and with autocatalytic amplification. Increasing activity with the intrinsic π acidity of benzenes, naphthalenediimides (NDIs) and perylenediimides (PDIs) support that anion-π interactions account for function. Rate enhancements maximize at 270 for anion-π catalysis on fullerenes and at 5100 M-1 for autocatalysis. The occurrence of anion-π autocatalysis is confirmed with increasing initial rates in the presence of additional product. Computational studies on autocatalysis reveal transition state and product forming a hydrogen-bonded noncovalent macrocycle, like holding their hands and dancing on the active π surface, with epoxide opening and nucleophile being activated by anion-π interactions and hydrogen bonds to the product, respectively.