<i>Dendrimeric bis(piperazine)</i> coupled <i>schiff base</i> ligand synthesized with mannich reaction and its Pd(II), <i>oxo</i>-V(IV) complexes supported on <i>nano</i>-magnetite: Most effective, green and recoverable catalyses under microwave powe

Vitamin K₃ is a synthetic member of Vitamin K group used as a nutritional supplement. The best recyclable and very efficient heterogenous catalysts containing piperazine substituents used in the green synthesis of vitamin K₃ without any hazardous waste in short reaction times under microwave power. Firstly, N-methyl-substituted piperazine was coupled with 2,4-dihydroxybenzaldehyde as the route of Mannich reaction and the synthesized compound was reacted with aminosilane modified nano-structured Fe₃O₄. After, Pd(II) and <i>oxo</i>-V(IV) complexes of the obtained ligant were synthesized and all the synthesized compounds were characterized by using FT-IR, LC-MS/MS, SEM, EDX, TEM, TG/DTG/DTA, XRD and NMR techniques. The microwave assisted catalytic activities of the synthesized nano-Fe₃O₄ supported Pd(II) and <i>oxo</i>-V(IV) type complexes were investigated in the oxidative catalytic synthesis of vitamin K₃ from 2-methyl-napthtalene (2MN) using green oxidant (H₂O₂). Heterogenous nano-Fe₃O₄-supported-Pd(II) complex was showed one of the best efficient catalytic activites with highly selectivities compared to the literature. The converison of Fe₃O₄@SiO₂-L-Pd(II) complex was calculated as 91.29 ± 0.37% with a selectivity of 72.39 ± 0.46%. Fe₃O₄@SiO₂-LOV(IV) complex was conversed the substrate with 88.56 ± 0.48% and 61.25 ± 0.24 selectivity. Pd(II) complex can be used in five cycles as an efficient catalyt in the recycles process with a selectivity of 45.57 ± 0.41% in the 91.33 ± 0.29% conversion.