Trifunctional Covalent Triazine And Carbonyl Based Polymer As A Catalyst For One-Pot Multistep Organic Transformation

Trifunctional covalent triazine and carbonyl based polymer with acid-base and metal active sites (CTCP-SO3HEDA/Pd) was synthesized by a multistep friedel-crafts reaction, post-synthetic sulfonation, schiff base condensation and metal nanoparticle incorporation. CTCP-SO3H-EDA/Pd was characterized by FT-IR, N2 sorptiondesorption isotherm, elemental analysis, ICP-OES, TEM-EDS and TEM. CTCP-SO3H-EDA/Pd was evaluated as a heterogeneous catalyst for the conversion of 1-(dimethoxymethyl)-3-nitrobenzene into 2-(3-aminobenzylidene) malononitrile via a three step deacetylation-Knoevenagel and transfer hydrogenation reaction in one domino process. The cooperation of SO3H acidic sites, EDA and uniformly distributed Pd nanoparticles greatly facilitated the one-pot reaction and produced good yield of the desired product with high selectivity. The catalyst was recovered by simple centrifugation and could be reused for five runs with minor loss of catalytic activity and selectivity. A plausible mechanism for deacetylation, C-C bond formation and subsequent chemoselective reduction of nitro functionality over CTCP-SO3H-EDA/Pd was also proposed.