A photocatalytic protocol for the synthesis of β-amino acid ester and β-amino ketone derivatives is developed using simple and easy-to-synthesize oxime oxalate and oxime phenylglyoxylate as difunctionalization reagents. These bifunctional reagents were used to generate iminyl and alkoxycarbonyl/benzoyl radicals via energy transfer-promoted N–O bond homolysis and decarbonation. More than 40 highly functionalized β-amino acid ester and β-amino ketone derivatives were obtained in 60–86% yields by taking advantage of different kinds of olefins such as ordinary aromatics, α-trifluoromethylstyrenes and β-CF₃-1,3-enynes.