Preparation and Asymmetric Induction Evaluation of the First Ephedrine-Based Ligands Immobilized on Magnetic Nanoparticles.

Herein, the synthesis and catalytic activity of two ephedrine-based catalysts and two ephedrine-based magnetic nanoparticle-supported catalysts are reported. All catalysts developed were tested in the addition of diethylzinc to aromatic aldehydes and in the Henry reaction. The homogeneous catalysts showed moderate catalytic activity in the organozinc addition and good activity in the Henry reaction, whereas in the case of the nanocatalyst, it was not effective in the addition of diethylzinc to aldehydes and gave reasonable results in the Henry reaction.

Linear β-amino alcohol catalyst anchored on functionalized magnetite nanoparticles for enantioselective addition of dialkylzinc to aromatic aldehydes.

A linear β-amino alcohol ligand, previously found to be a very efficient catalyst for enantioselective addition of dialkylzinc to aromatic aldehydes, has been anchored on differently functionalized superparamagnetic core-shell magnetite-silica nanoparticles (1a and 1b). Its catalytic activity in the addition of dialkylzinc to aldehydes has been evaluated, leading to promising results, especially in the case of 1b for which the recovery by simple magnetic decantation and reuse was successfully verified.