ethyl-3-bromopyruvate (Et-3-BrP), using the Passerini three-component reaction, to fully substitute α-amidoester (β-dicarbonyl) derivatives was investigated. The method is efficient for the one-step preparation of highly functionalized β-dicarbonyl derivatives containing N-protected amino acid residues and aliphatic, aromatic, and heteroaromatic carboxylic ester derivatives.