CuO‐catalyzed 1,3‐addition of diaryliodonium triflates to diazo esters was realized. This new strategy forms a series of triflate‐substituted β‐aryloxyl acrylate compounds with good tolerance of functional groups and excellent regioselectivity. Mild reaction conditions are enough, and strong acids or bases are not required. Easy manipulation and good step‐economy are further advantages. The alkenyl triflate products can be further modified via cross‐coupling reactions to generate derivatized products.