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

Abstract

Abstractβ‐(2‐Aminophenyl)‐α,β‐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 β‐(2‐aminophenyl)‐α,β‐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 β‐(2‐aminophenyl)‐α,β‐ynoates as substrates.magnified image