Synthesis of quinolines and fused pyridocoumarins from N-propargylanilines or propargylaminocoumarins by catalysis with gold nanoparticles supported on TiO2

[5,6]-Fused pyridocoumarins are prepared under mild conditions in excellent yields through the activation of the triple bond of 6-propargylaminocoumarins by gold nanoparticles supported on TiO2. The analogous reaction of N-propargylanilines with Au/TiO2 or Au/Al2O3 resulted in the formation of quinolines.