Investigation of the palladium-catalysed cyclisation of α-amido malonates with propargylic compounds

Abstract

Abstract The palladium-catalysed cyclisation of propargylic electrophiles with nucleophiles represents a useful synthetic approach for the rapid construction of heterocyclic building blocks. However, these cyclisation reaction processes often pose a number of challenges due to the need for the simultaneous control of chemo-, regio- and stereoselectivity. Herein, we disclose the discovery of α-amido malonates as novel bis-nucleophiles in the highly chemo- and regioselective, as well as moderately enantioselective, palladium-catalysed cyclisation with propargylic compounds to afford a broad range of functionalised dihydrooxazine heterocycles. The new dihydrooxazine products will expand the suite of heterocycles available to medicinal chemists, and prompt the investigation of unchartered bis-nucloeophiles in palladium-catalysed cyclisation reactions en route to novel classes of heterocycle.