Nucleophilic Substitution at the Guanidine Carbon Center via Guanidine Cyclic Diimide Activation.

Despite the electron-deficient nature of the guanidine carbon centers, nucleophilic reactions at these sites have been underdeveloped because of the resonance stabilization of the guanidine group. We propose a guanidine C-N bond substitution strategy entailing the formation of guanidine cyclic diimide (GCDI) structures, which effectively destabilize the resonance structure of the guanidine group. In the presence of acid additives, the guanidine carbon center of GCDIs undergoes nucleophilic substitution reactions with various amines and alcohols.