Recently, acid–base bifunctional catalysts have been considered due to their abilities, such as the simultaneous activation of electrophilic and nucleophilic species and their high importance in organic syntheses. However, the synthesis of acid–base catalysts is problematic due to the neutralization of acidic and basic groups. This work reports a facial approach to solve this problem via the synthesis of a novel bifunctional polymer using inexpensive materials and easy methods. In this way, at the first step, heterogeneous poly (styrene sulfonic acid‐n‐vinylimidazole) containing pentaerythritol tetra‐(3‐mercaptopropionate) (PETMP) and trimethylolpropane trimethacrylate (TMPTMA) cross‐linkers were synthesized in the pores of a mesoporous silica structure using click reaction as a novel bifunctional acid–base catalyst. After that, Ni‐Pd nanoparticles supported on poly (styrenesulfonic acid‐n‐vinylimidazole)/KIT‐6 as a novel trifunctional heterogeneous acid–base‐metal catalyst was prepared. The prepared catalysts were characterized by various techniques like FT‐IR, TGA, ICP‐AES, DRS‐UV, TEM, FE‐SEM, EDS‐Mapping, and XRD. The synthesized catalysts were efficiently used as bifunctional/trifunctional catalysts for one‐pot, deacetalization‐Knoevenagel condensation and one‐pot, three‐step and a sequential reaction containing deacetalization‐Knoevenagel condensation‐reduction reaction. It is important to note that the synthesized catalyst showing high chemo‐selectivity for the reduction of nitro group, alkenyl double bond and ester group in the presence of nitrile. Moreover, it was found that the different nanoparticles including Ni, Pd, and alloyed Ni‐Pd showing different chemo‐selectivity and catalytic activity in the reaction.

Stoichiometric amounts of various oxidants have long been employed for the oxidation of organic compounds. The major drawback of this method is the amount of toxic waste produced, which is in sharp contrast to principles of green chemistry. In catalytic dehydrogenation pathways, hydrogen carrier organic compounds (HCOCs) containing O−H, C−H, and N−H bonds can be transformed to their oxidized forms by removing two hydrogen atoms from the starting materials. Among the homogeneous transition metal‐ligand complexes that have been applied in a catalytic dehydrogenative approach, phosphine ligands have frequently been used. Over the past decades, phosphine‐free ligand systems have since been developed and implemented in various organic reactions to overcome the drawbacks associated with phosphine‐based catalysts. The aim of this review is to summarize the use of non‐phosphinic ligand‐metal complexes in organic transformations proceeding by a dehydrogenative pathway.