MoOPH

Other names: molybdenum oxide-pyridine-HMPA, oxo­di­peroxy­molybdenum(pyridine)(hexa­methyl­phosphoric tri­amide), Vedejs Reagent

MoO₅·P(NMe₂)₃O·C₆H₅N

43/50 uncommon

MoOPH (molybdenum oxide-pyridine-HMPA) is a versatile oxidizing agent developed by Edwin Vedejs in 1974, and as such it is sometimes referred to as Vedejs Reagent. This crystalline green-blue solid contains a molybdenum(VI) center coordinated to two peroxide groups, a terminal oxo ligand, a pyridine molecule, and a hexamethylphosphoramide (HMPA) ligand. What makes MoOPH particularly valuable is its ability to perform highly regioselective oxidations, especially the hydroxylation of enolates and other nucleophilic carbon species. It excels at α-hydroxylation of ketones and esters with high control, placing the hydroxyl group opposite to existing substituents. MoOPH has proven crucial in the synthesis of complex natural products, including prostaglandins and macrolide antibiotics, where precise placement of hydroxyl groups is essential.