Palladium-catalysed imidoylative difunctionalization of allenes: access to quinolines and indeno[1,2-b]quinolines

Abstract

A palladium-catalysed three-component imidoylative amination, etherification and alkylation of allenes for the construction of multisubstituted quinolines from 2-allenylaryl isocyanides, aryl iodides and nucleophiles has been developed. Amines, phenols, malononitriles and 3-F oxindoles acted as efficient nucleophiles to attack the allyl-palladium intermediate, affording diverse quinoline derivatives. Furthermore, a C–H bond alkylation reaction was disclosed when the reaction was carried out in the absence of a nucleophile, offering straightforward access to indeno[1,2-b]quinoline scaffolds with the formation of two rings in one step. The annulation reaction features broad functional group tolerance and mild reaction conditions.