Remarkably fast and selective aromatization of Hantzsch esters with MoOCl4 and MoCl5: a chemical model for possible biologically relevant properties of molybdenum-containing enzymes.

Mo(VI) and Mo(V) salts both react selectively with Hantzsch esters to produce substitute pyridines in good-to-excellent yield (75-99%). The remarkable reactivity and selectivity of MoOCl(4) under reflux of acetonitrile and MoCl(5) in dichloromethane at room temperature encouraged us to propose that molybdenum-containing enzymes (such as xanthine or aldehyde oxidase) also participate to some degree in the metabolism of 1,4-dihydropyridine drugs in the liver analogous to NADH in the respiratory chain.