Beschleunigung von Substitutionsreaktionen eines Phosphorsäurediesters durch Bis(guanidinium)‐Verbindungen

Acceleration of Substitution Reactions of a Phosphoric Acid Diester by Bis(guanidinium) Compounds Ion‐pair coordination of phosphoric acid diesters with positively charged guanidines may cause large rate accelerations in substitution reactions. Here we present a comparative study on the catalytical influence of several mono‐ bis‐ and tris(guanidines) and of other cationic compounds. Large rate effects occur if 1,3‐bis(aminomethyl)benzene or 1,2‐ethylenediamine are used as spacers. Further acceleration can be achieved by exchanging guanidinium groups by 2‐aminoimidazolines. The 4800‐fold rate enhancement seen in the best case demonstrates the importance of the bis(guanidinium) moiety of staphylococcal nuclease and gives good perspectives towards future uses of guanidinium compounds as RNA cleaving agents. magnified image