Metal‐Free and Diastereoselective Synthesis of 4‐Oxa‐δ‐Lactams with 2‐Aza‐3‐silyloxy‐1,3‐butadienes and Fluoroalkyl Acylsilanes

Herein, we report a diastereoselective [4+2] cycloaddition reaction of 2‐aza‐3‐silyloxy‐1,3‐butadienes and fluoroalkyl acylsilanes for the synthesis of fluoroalkyl 4‐oxa‐δ‐lactams without a metal catalyst or an additive under open‐to‐air conditions. The reaction features mild conditions, high efficiency and excellent diastereoselectivity, exhibiting a broad substrate scope and good functional group tolerance.