The Stabilities of Metal Complexes of Oxygen-containing Heterocyclic Compounds. Maltol¹

A New Role for Old Ligands: Discerning Chelators for Zinc Metalloproteinases

“…Recently, as part of a program to develop novel MMPi, we described 11 chelators with improved potency for use in full-length inhibitors . These compounds show substantially improved MMP inhibition, but like hydroxamic acids they are avid chelators of a variety of transition metal ions and thereby are not likely to improve the selectivity of MMPi for Zn 2+ -metalloproteins. , …”

“…7 These compounds show substantially improved MMP inhibition, but like hydroxamic acids they are avid chelators of a variety of transition metal ions and thereby are not likely to improve the selectivity of MMPi for Zn 2+ -metalloproteins. 8,9 In an effort to identify potential ZBGs with both improved affinity and selectivity for the active site Zn 2+ ion, compounds 1-7 were investigated (Figure 1). These compounds consist of a variety of nitrogen and mixed nitrogen/oxygen donor-atom chelators including pyridine-and aza-macrocycle-based ligands.…”

Synthesis and characterization of nickel(II) maltolate complexes containing ancillary bisphosphine ligands

“…For example, the octahedral nickel(II) complex [Ni(maltolato) 2 (H 2 O) 2 ] (2) has been known for some time [9][10][11], and in a recent report [12] was prepared by the reaction of nickel(II) acetate with maltol in the presence of NaOH, the complex being characterized by an X-ray diffraction study. The stabilities of the complexes of divalent metal ions (including Ni 2þ ) with maltol had been previously studied [13]. In this article, we describe the synthesis of some new nickel(II) complexes containing maltolate and ethyl maltolate ligands with ancillary bis(phosphine) ligands, dppe [1,2-bis (diphenylphosphino)ethane] or dppp [1,3-bis(diphenylphosphino)propane].…”