Enantioselective Synthesis of g-Lactams

Significance

The authors report an enantio­selective synthesis of halo-substituted γ-lactams. An enantioselective 1,4-addition of 1,2-dinucleophiles to α,β-dihalogenated acrylate esters was achieved by using dihydrocinchonine-derived phase transfer catalyst 1. Immediate cyclization delivered the desired products after recrystallization from the crude reaction mixture in good yields (62-90%) and excellent enantioselectivities of er > 99.5:0.5. Additionally, the obtained products were shown to be versatile substrates for cross-coupling, hydrogenation and addition reactions.