Iron(III) Chloride as a Mild Catalyst for the Dearomatizing Cyclization of N-Acylindoles

J Org Chem. 2020 Oct 2;85(19):12160-12174. doi: 10.1021/acs.joc.0c01373. Epub 2020 Sep 16.

Abstract

A catalytic approach for the preparation of indolines by dearomatizing cyclization is presented. FeCl3 acts as a catalyst to afford tetracyclic 5a,6-dihydro-12H-indolo[2,1-b][1,3]benzoxazin-12-ones in good yields. The cyclization also proceeds with tosylamides forming C-N bonds in 53% yield.