A new and efficient protocol to synthesize substituted benzo[b]carbazole derivatives has been demonstrated involving iron-catalyzed domino isomerization/cyclodehydration sequences from substituted 2-[(indoline-3-ylidene)(methyl)]benzaldehyde derivatives. The substrates could be easily made via Pd-catalyzed domino Heck-Suzuki coupling from 2-bromo-N-propargylanilide derivatives in high yields. Notably, the generality and efficiency of this two-stage domino strategy was further exemplified by the synthesis of a polycyclic benzofuran derivative.

A simple and convenient approach was developed to the selective synthesis of 3‐substituted indoles and benzofurans by the isomerization of 3‐methyleneindoline and benzofuran derivatives catalyzed by Fe(OTf)3. The salient features of this method are the easy availability of substrates, high yield, mild reaction conditions, tolerance of a variety of functional groups, and use of an environmentally friendly catalyst. A possible mechanism has also been proposed for the isomerization process.

A general and efficient synthesis of tetracyclic indolo[2,3-b]quinoline motifs with diverse functional groups is achieved through a simple but conceptually different annulation strategy in excellent yields.

An Fe(OTf)-catalyzed 1,5-enyne cycloisomerization via 5-endo-dig cyclization is described for the synthesis of 3-(1-indenyl)indole derivatives. Since a variety of 1,5-enynes are readily accessible via Heck-Suzuki coupling, this strategy provides a rapid and easy access to a wide range of highly substituted 3-(1-indenyl)indoles in good yields.

In this study we have developed an efficient synthesis of 1,2-dihydroquinoline and dihydrobenzo[b]azepine derivatives involving the iron(III) chloride intramolecular alkyne-carbonyl metathesis reaction for the first time. Various functionalized 1,2-dihydroquinolines and dihydrobenzo[b]azepines were prepared from easily accessible substrates in the presence of environmentally friendly and inexpensive iron(III) chloride (10 mol%) under mild conditions. The method is applicable to a wide range of substrates containing different functional groups and furnishing products in good to excellent yields. This methodology was further extended to the one-pot synthesis of 3-acyl quinolines via alkyne-carbonyl metathesis/detosylation/aromatization of N-propargyl-2-aminobenzaldehyde/acetophenone derivatives by the addition of NaOH/EtOH. While many Lewis acid and Brønsted acid catalysts were investigated, anhydrous iron(III) chloride turned out to be the best catalyst for this transformation.