The phospha-Michael addition of dimethyl- and diphenylphosphites to the η1-N-maleimidato ligand: Inhibition of serine hydrolases by half-sandwich metallocarbonyl azaphosphonates

Dialkyl- and diphenyl phosphites react with the (η5-C5H5)M(CO)x(η1-N-maleimidato) (M = Fe, Mo; x = 2 or 3) complexes giving products of the phospha-Michael addition to the η1-N-maleimidato ligand. One of these complexes (M = Fe, x = 2) was characterized by X-ray diffraction. The synthesized metallocarbonyl azaphosphonates and the corresponding iron phosphonic acid act as inhibitors of certain serine hydrolases (AChE and BChE). The kinetic assays were performed and revealed that inhibition mechanism depends strongly on the enzyme and the structure of the inhibitor.