A convenient protocol for a zinc-catalysed synthesis of electron-poor indoles

A convenient catalytic protocol for the synthesis of electron-poor indoles was envisioned. A cyclisation reaction of electron-deficient 2-(alkynyl)-anilines, catalysed by Zn(II) salts, was successfully developed and applied to the synthesis of an API precursor. A two-step one-pot procedure starting from aniline derivatives was successfully developed. The use of a readily available, non-noble metal further enhanced the value of the protocol.