Postfunctionalized Porous Polymeric Aromatic Frameworks with an Organocatalyst and a Transition Metal Catalyst for Tandem Condensation–Hydrogenation Reactions

Novel heterogenized bifunctional catalysts were prepared combining a rhodium complex with a pyrrolidine on porous polymeric aromatic frameworks (PAFs) based on tetraphenyladamantane and tetraphenylmethane subunits. These new systems catalyze efficiently tandem Knoevenagel condensation and hydrogenation of the resulting olefin. These tandem reactions represent an easy and selective methodology for monoalkylation of methylene active compounds from aldehydes. The obtained bifunctional PAFs exhibit high activity and excellent stability in the cascade reactions and can be recycled up to ten times in a productive process.