Microporous Polymers as Macroligands for Pentamethylcyclopentadienylrhodium Transfer-Hydrogenation Catalysts

Herein, we report the synthesis of two bipyridine-based porous polymers and their use as platforms for the heterogenization of pentamethylcyclopentadienylrhodium catalytic species. These highly stable heterogeneous catalysts demonstrate their efficiency in the transfer hydrogenation of -aryl ketones. Moreover, we show that their catalytic activity is similar to that of homogeneous analogues, highlighting the absence of diffusion limitations in the solids. We rationalize the differences in the measured activities by using the Hammett parameter as a descriptor of the electronic environment of the catalytic site in both homogeneous and heterogeneous systems.