Gold‐Catalyzed Synthesis of Dibenzo[1,5]diazocines from β‐(2‐Aminophenyl)‐α,β‐ynones

Abstract

beta-(2-Aminophenyl)-alpha,beta-ynones afforded exclusively challenging dibenzo[1,5]diazocines by means of (JonPhosAuNCMe)SbF6 catalysis. In contrast with the known gold-catalyzed reaction path of 2-alkynylanilines that leads to indoles, ynones underwent an auto intermolecular hydroamination. This process resulted finally in the formation of an eight-membered ring, likely through a selective 8-exo-dig intramolecular hydroamination that prevailed over the possible cyclocondensation reaction (that would result in the formation of 4-aminoquinoline derivatives). The easy availability of beta-(2-aminophenyl)-alpha,beta-ynones and the simple cyclization procedure make this approach suitable for the preparation of a wide range of useful dibenzodiazocines. The methodology can be extended to the use of beta-(2-aminophenyl)-alpha,beta-ynoates as substrates

Reaction of β‐(2‐aminophenyl)‐α,β‐Ynones with Tosyl Isocyanate: Experimental and Computational Investigations

“…More recently, β‐(2‐aminophenyl)‐α,β‐ynones afforded 3‐unsubstituted 2‐acylindoles in good yields in the presence of 20 mol% AgOTf under (microwave) MW heating . Furthermore, the same substrates resulted starting reagents for the preparation of a wide range of useful dibenzodiazocines through a gold‐catalyzed tandem auto intermolecular hydroamination followed by a regioselective 8‐exo‐dig ‐cycloamination …”

2‐(Alkynyl)anilines and Derivatives — Versatile Reagents for Heterocyclic Synthesis

“…It has been found that β‐(2‐aminophenyl)‐α,β‐ynones 181 under catalysis with (JonPhosAuNCMe)SbF 6 are selectively dimerized to form dibenzo[1,5]diazocines 182 (Scheme 57). [159] The reaction starts with an intermolecular hydroamination, which is followed by an intramolecular hydroamination.…”

Annulation of 2‐Alkynylanilines: The Versatile Chemical Compounds

“…When dimerization of β‐(2‐aminophenyl)‐α,β‐ynones 57 is catalyzed by (JonPhosAuNCMe)SbF 6 , a series of dibenzo[1,5]diazocine 208 is formed through 8 ‐exo‐dig intramolecular hydroamination process (Scheme 64). [130] …”