Scheme 2.

Reaction scope. A) Scope of γ‐lactams. B) Scope of γ‐lactones. [a] General conditions I: olefin (1 equiv), fac‐Ir(ppy)₃ (1 mol%), CDFAA (2 equiv), MeCN (0.03 M), blue LEDs, rt, 12 h, isolated yields. [b] X‐Ray figures were created with the CYLview 2.0 Software, Legault, C. Y., Sherbrooke University 2020 (www.cylview.com). Hydrogen atoms were omitted for clarity. [c] Solvent EtCN (0.03 M). [d] Solvent iPrCN (0.03 M). [e] General conditions II: olefin (1 equiv), fac‐Ir(ppy)₃ (1 mol%), CDFAA (2 equiv), DMF (0.17 M), blue LEDs, rt, 12 h, isolated yields. [f] Reaction conducted for 24 h.