Silica supported phosphomolybdic acid, an eco-friendly heterogeneous catalyst, has been found to be highly efficient for Friedlander synthesis of quinolines in excellent yields. A variety of ketones afford the quinolines smoothly. The catalyst can be easily recovered and reused.

The interesting effects of the linker and microenvironment on the recyclability of well-defined silica-supported catalysts were examined, which demonstrated the excellent activity and reusability for the ring-closing metathesis (RCM) of a number of substrates.