Copper‐catalyzed [3+2+1] Annulation of Anthranils with Phenylacetaldehydes: Synthesis of 8‐Acylquinolines

Abstract

A Cu0‐catalyzed protocol is proposed for the synthesis of 8‐acylquinolines through a [3+2+1] annulation starting from anthranils and phenylacetaldehydes. This protocol is of particular interest in preparing 8‐aldehyde quinolines, which have been hard to access so far. Both AgOTf and dioxygen played an important role in the reaction. C3‐heterocycle or phenylethylene substituted anthranils could also be employed in the reaction. An interesting esterification of aldehyde was observed.

Copper-Catalyzed [4+1+1] Annulation of Ammonium Salts and Anthranils: Synthesis of 2,3-Diaroylquinolines

“…In this regard, the utilization of onium ylides through annulation is a highly valuable approach to accessing heterocycles . Ammonium salts have played an important role in the synthesis of bioactive heterocyclic compounds through [ n +1] annulation due to their valuable usage, high safety and easy availability. , Following our recent research focused on construction of quinolines, herein, we report a novel synthetic method to synthesize 2,3-diaroylquinolines through a copper­(I)-catalyzed [4+1+1] annulation of ammonium salts with anthranils (Scheme , eq c). It should be noteworthy that this work exhibited significant advantages over our previous work in the terms of higher yields, more broad substrate scope and the emission of the use of expensive silver salts as the cocatalyst …”