Synthesis of Pyrrolo[1,2-a]indoles via (3+2)-Annulations of (Aza)-para-Quinone Methides with Indoles

Abstract

An efficient and straightforward Brønsted acid mediated (3+2)-annulation of (aza)-para-quinone methides, generated in situ from propargylic alcohols and indoles, has been developed involving 1,8-conjugate addition/5-endo annulation cascade. This protocol affords a mild and effective method for the construction of synthetically important and structurally interesting functionalized pyrrolo[1,2-a]indoles.