Highly efficient Au(I)-catalyzed intramolecular addition of β-ketoamide to unactivated alkenes

N-Alkenyl beta-ketoamides undergo cyclization in the presence of Au[P(t-Bu)(2)(o-biphenyl)]Cl (5 mol %) and AgOTf (5 mol %) under mild conditions with excellent regioselectivities and yields. The reaction provides an efficient method to prepare highly substituted lactams.