A very efficient NHC-catalyzed lactamization reaction is reported. For most cases, the ring expansion reaction proceeds to cleanly furnish five- and six-membered N-Ts and N-Bn lactams, without the need for further purification. Evidence is presented suggesting a dual role for the stoichiometric base: (1) deprotonation of the triazolium precatalyst and (2) activation of the nitrogen leaving group through
据报道,NHC催化的内酰胺化反应非常有效。在大多数情况下,进行扩环反应可干净地提供五元和六元N -T和N -Bn内酰胺,而无需进一步纯化。提出的证据表明
化学计量的碱具有双重作用:(1)三唑鎓预催化剂的去质子化和(2)通过氢键活化氮离去基团。