Abstract γ-Lactams were synthesized from N-tosylhomoallylamines by a carbonylation reaction catalyzed by palladium and copper salts under the normal pressure of CO and O2 at room temperature. Monocarbonylation proceeded by the use of [PdCl2(CH3CN)2] and CuCl2 to afford 3-methyl-2-pyrrolidones, while the use of PdCl2 and CuCl switched the reaction from monocarbonylation to dicarbonylation to produce alkyl 2-oxopyrrolidine-3-acetate in good yields, respectively.