Bicyclic guanidinium derivatives with different side arms efficiently catalyze the conjugate addition of pyrrolidine to 2-(5H)-furanone, the best results being obtained when the two chains are an aromatic residue and an amine or imidazole, respectively. The catalysis is likely due to the development of strong ion-pairing and hydrogen-bonding in the transition state.
具有不同侧臂的双环
胍鎓衍
生物有效地催化
吡咯烷与2-(5 H)-
呋喃酮的共轭加成,当两条链分别为芳族残基和胺或
咪唑时,可获得最佳结果。该催化可能是由于过渡态中强离子对和氢键的发展所致。