Preparation of sub-microspherical Fe3O4@PDA-Pd NPs catalyst and application in catalytic hydroreduction reaction of halogenated aromatic nitro compounds to prepare halogenated aromatic amines

Abstract

BackgroundThe side reactions of dehalogenation or C–N coupling tend to occur when halogenated aromatic amines are prepared by catalytic hydrogenation reduction of halogenated aromatic nitro compounds. In this paper, we prepared the sub-microspherical Fe3O4@PDA-Pd NPs catalyst apply it efficiently in the hydrogenation reduction of halogenated aromatic nitro compounds to prepare the halogenated aromatic amines under atmospheric pressure. The catalyst shows a high selectivity of greater than 96% and can effectively inhibit the occurrence of the side reactions of dehalogenation and C–N coupling.ResultsThe optimum condition of the hydroreduction reaction is when tetrahydrofuran is used as solvent and the reaction happens at 50 °C for 5 h. The selectivity of the chlorinated aromatic amine and the fluorinated aromatic amine products exceed 99% and the yield exceeds 90%. Only a small amount of dehalogenated products and C–N coupling by-products were produced in the brominated aromatic compound and the iodinated aromatic compound.ConclusionWe developed a promising method for preparing the superparamagnetic and strongly magnetic Fe3O4@PDA core–shell sub-microsphere-supported nano-palladium catalyst for catalyzing the hydrogenation reduction of halogenated aromatic nitro compounds. The halogenated aromatic amines were efficiently and highly selectively prepared under atmospheric pressure, with the side reactions of dehalogenation and C–N coupling effectively inhabited simultaneously.

ZIF-Derived Co-Based Catalysts for Efficient Hydrogenation of Aromatic Compounds: the Study of the Co–Nx Active Sites

“…Aromatic amines are important organic raw materials and intermediates, widely used in synthetic dyes, chemical fiber, pesticides, rubber additives, and other industries. − At present, the aromatic amines are mainly produced by reduction processes from corresponding aromatic nitro compounds, including the metal reduction method, electrochemical reduction, hydrazine hydrate reduction, and catalytic hydrogenation . Among these methods, the catalytic hydrogenation is being increasingly valued for its environmental friendliness, high yields, and catalytic recyclability, , and has become the most promising green production method for it could effectively solve the shortcomings of high pollution and high energy consumption in the traditional reduction method.…”

“…Aromatic amines are important organic raw materials and intermediates, widely used in synthetic dyes, chemical fiber, pesticides, rubber additives, and other industries. − At present, the aromatic amines are mainly produced by reduction processes from corresponding aromatic nitro compounds, including the metal reduction method, electrochemical reduction, hydrazine hydrate reduction, and catalytic hydrogenation . Among these methods, the catalytic hydrogenation is being increasingly valued for its environmental friendliness, high yields, and catalytic recyclability, , and has become the most promising green production method for it could effectively solve the shortcomings of high pollution and high energy consumption in the traditional reduction method. The catalysts for aromatic nitro compounds hydrogenation are classified into noble-metal catalysts (Pt, Pd, Ru) and non-noble metal (Ni, Fe, Cu, Co) catalysts.…”

Copper‐Decorated Magnetite Polydopamine Composite (Fe3O4@PDA): An Effective and Durable Heterogeneous Catalyst for Pyranopyrazole Synthesis

“…Then, CuCl 2 was decorated on the Fe 3 O 4 @PDA′s surface, through coordination to the amino groups of the Fe 3 O 4 @PDA submicrospheres (Scheme 2). [47] …”

The preparation of new palladium (II) complexes with Schiff base type ligands and its impregnated Al2O3 materials: As the catalysts for degradation/reduction of organic dyes

“…In particular, the catalytic activity of palladium materials in reduction reactions is well known. [ 42–44 ] Although there are many nanocatalysts which are used for the degradation/reduction of organic compounds in the presence of NaBH4 in water, transition metal (TM) or supported TM catalysts are very rare (Table 3).…”