Synthesis of novel magnetic nanoparticles with urea or urethane moieties: Applications as catalysts in the Strecker synthesis of α‐aminonitriles

Abstract

Four novel magnetic nanoparticle catalysts with urea or urethane moieties are reported. The silica‐coated magnetic nanoparticles were simply functionalized via addition of 3‐(triethoxysilyl)propylisocyanate (TESPIC), amine or amino alcohol. TESPIC with dual labile functional groups was used as a suitable precursor for the synthesis of urethane‐based catalysts. The newly synthesized catalysts were fully characterized using a variety of techniques. These functionalized magnetic nanoparticles were used as reusable catalysts in the Strecker synthesis of α‐aminonitrile derivatives under solvent‐free conditions at 50 °C.

Core–Shell Pluronic-Organosilica Nanoparticles with Controlled Polarity and Oxygen Permeability

“…The reaction is fast and quantitative, as it results from NMR and MS characterizations (see Supporting Information), thus allowing us to use the precursors without further purification. Analogous reactions were previously used to functionalize the surface of nanomaterials for catalytic purposes , or to modify mesoporous nanoparticles for drug delivery …”

Three‐component solventless Strecker synthesis of α‐aminonitriles catalysed by a renewable sulfonated nanoporous carbon catalyst (CMK‐5‐SO3H)

“…As part of our interest in heterogeneous acid‐catalysed reactions, we anticipated that CMK‐5‐SO 3 H can be used as an efficient catalyst for the promotion of reactions that need the use of an acidic catalyst to speed them up.…”

“…However, the Strecker reaction has drawbacks, in particular due to the volatile and highly toxic nature of HCN. Among various cyanide sources such as HCN, KCN, NaCN, Bu 3 SnCN, K 4 [Fe (CN) 6 ] and trimethylsilyl cyanide (TMSCN), TMSCN is a desirable cyanide reagent, due to its safety, efficiency and availability. It is also noteworthy that TMSCN cannot transfer to electrophiles by itself and needs a catalyst for its activation.…”

Overview on magnetically recyclable ferrite nanoparticles: synthesis and their applications in coupling and multicomponent reactions

“…Only 1 mg of each catalyst was active enough to catalyse the reaction and could be used for 7 times without loss in catalytic activity (Scheme 29). 164 Gharib et al have achieved the synthesis of a-aminonitriles using copper ferrite (CuFe 2 O 4 ) nanocatalyst in one pot by the reaction of various aldehyde derivatives, amines and trimethylsilyl cyanide at room temperature by using water as a solvent. The catalyst was synthesized by citrate gel precursor method by reacting copper nitrate and iron nitrate in citric acid solution at pH ¼ 7 maintained by adding ammonia at higher temperature (Scheme 30).…”

“…Only 1 mg of each catalyst was active enough to catalyse the reaction and could be used for 7 times without loss in catalytic activity ( Scheme 29 ). 164 …”