Lanthanide–EDTA complexes covalently bonded on Fe3O4@SiO2 magnetic nanoparticles promote the green, stereoselective synthesis of N-acylhydrazones

Abstract

In the last few years, many synthetic methods have been developed using magnetic nanomaterial-based catalysts with considerable advantages for the efficiency, selectivity and applicability of green procedures. In this work, lanthanide–EDTA complexes covalently bonded on Fe₃O₄@SiO₂ magnetic nanoparticles (Fe₃O₄@SiO₂-xN-EDTA–Ln³⁺, with x = 1, 2, or 3 N spacer groups, and Ln³⁺ = La³⁺, Ce³⁺, Sm³⁺, Eu³⁺, Gd³⁺, Tb³⁺, Er³⁺ or Yb³⁺) were prepared and investigated as a heterogeneous catalyst for the synthesis of N-acylhydrazones. The target molecules were obtained in good to excellent yields, exclusively as E-diastereomers after short reaction times under mild conditions and low concentration of the easily recyclable catalyst.