Palladium-catalyzed intramolecular asymmetric hydrocyclopropanylation of alkynes: synthesis of cyclopropane-fused γ-lactams.

A palladium-catalyzed intramolecular asymmetric hydrocyclopropanylation of alkynes C(sp)-H activation has been developed for the synthesis of cyclopropane-fused γ-lactams. The presented strategy proceeds in a selective and 100% atom-economical manner. A range of cyclopropane-fused γ-lactams were prepared from readily available substrates in good yields and enantioselectivities with a chiral phosphoramidite ligand.