Cyclopalladated Azo–linked Porous Polymers in C–C Bond Forming Reactions

We designed a new cyclopalladated porous polymer (cyclo‐Pd(II)/PP‐2) with up to 20.7 wt% of Pd and investigated it as a heterogeneous catalyst for C–C bond‐forming transformations. It was also shown to be an effective scavenger for Pd 2+ in solution. The palladacycles formed along the backbone of the azo‐linked porous polymer (PP‐2) with (Pd–N) and (Pd–C) bonds as were confirmed by a combination of spectroscopies. The cyclo‐Pd(II)/PP‐2 decomposed when used for Suzuki and Heck cross‐coupling reactions, and acyclic‐Pd/PP‐2 formed with Pd nanoparticles (NPs) bound to the PP‐2. The Suzuki couplings were highly efficient in water and exhibited excellent recyclability. The cyclo‐Pd(II)/PP‐2 was also an effective heterogeneous Lewis‐acid catalyst for stereoselective carbocyclization reactions.