Magnesium-Schiff base complexes

Fig. 10 Zinc and magnesium complexes based on Schiff base ligands...

Several metallic species other than titanium have been reported. Kobayashi showed that the tin(II) complex (16, Fig. 4) modified by cinchonine, a natural alkaloid, catalyzed the reaction to give the chiral cyanohydrin of cyclohexanecar-baldehyde in 90% ee [54]. Corey applied a magnesium complex of chiral bisox-azoline (17, Fig. 4) to the asymmetric silylcyanation. High selectivity of up to 95% ee was observed in the reactions of aliphatic aldehydes compared with benzaldehyde (52% ee) [55]. An aluminum complex of a peptide containing the phenolic Schiff base (7) was shown by Mori and Inoue to be an efficient catalyst for the addition of TMSCN to aldehydes [56,57]. 

Outside of the category of manganese porphyrins, one report indicates nuclease activity of a Schiff base manganese complex [Mn (salen)] when activated by magnesium monoperphthalate. Singlestrand breaks are observed at micromolar concentrations of the complex 163). 

Chisholm research group also reported a Schiff base complex of magnesium t-butoxide, 16, which is highly active in LA ROP but did not perform very stereoselective [19]. 

Homogeneous catalyst systems include transition metals, e.g. the cobalt Schiff base complex salcomine." "" " However, the quite expensive Schiff base cannot be recovered and recycled, which is a drawback of this method. Copper salts, e.g. CuCl2 and CuBr2, are widely used for the oxidation of TMP with molecular oxygen at larger scales." In addition, applications of the halides of Cr, Mn, Fe, Ni and Zn as catalysts have been described. Copper halides have been combined with earth metal halides, e.g. magnesium chloride." ... 

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