Abstract Three-component Mukaiyama–Mannich reaction of aldehydes, amines, and silyl enol diazoacetoacetate was efficiently carried out to afford δ-amino substituted-α-diazoacetoacetate derivatives catalyzed by 5 mol% of MgI2 etherate (MgI2•(OEt2)n) under mild and neutral reaction conditions in good to excellent yields. GRAPHICAL ABSTRACT