Ni(0) catalyzed one step synthesis of benzo[b][1,8] naphthyridin-5-ones from silyl-α-ketoalkynes in water

One-step synthesis of new benzo[b][1,8]naphthyridin-5-ones using a Ni(0) catalytic system in aqueous medium with mild conditions of pressure and temperature is described. It is very interesting to note that Ni(0) catalyst increases the rate of condensation of several α-ketoalkynes with 2-amino-4(1H)-quinolinone obtaining benzo[b][1,8]naphthyridin-5-ones in very high yield. In the absence of catalyst this condensation reaction takes 24 h with a product yield of <10%.