Asymmetric Synthesis of Pyrroloindolones by N‐Heterocyclic Carbene Catalyzed [2+3] Annulation of α‐Chloroaldehydes with Nitrovinylindoles1. Issue 51 (4th November 2013) - Ni, Qijian
Abstract NHC‐enolate plus 3: N‐heterocyclic carbenes (NHCs) serve as organocatalysts for the [2+3] annulation of nitrovinylindoles with α‐chloroaldehydes via an intermediate azolium enolate. The method provides trans‐disubstituted pyrroloindolones with good yields and excellent diastereo‐ and enantioselectivities. Further transformations lead to tetracyclic pyrrolo[1, 2‐a]indoles with potential psychotropic and other bioactivities.