Visible‐Light‐Triggered Hydroacylation of α ‐Imino Esters With α ‐Keto Esters via Substrate Self‐Catalysis

α ‐Ketoamides are important structural motifs in bioactive molecules. While conceptually efficient, direct acylation of imines toward α ‐ketoamides is hindered by their intrinsic instability and reactivity challenges. Here, we disclose a photochemical hydroacylation of α ‐imino esters with α ‐keto esters that operates without any transition metal or external photosensitizer. Mechanistic elucidation reveals that the α ‐keto ester plays a triple role: It serves as an unconventional hydroacylation donor, a visible‐light absorber, and a hydrogen‐atom abstractor, collectively enabling substrate‐driven self‐catalysis. This strategy provides rapid access to structurally diverse α ‐ketoamide derivatives (44 examples) with high yields (up to 97%) under mild, environmentally benign conditions. By integrating multifunctional substrates and self‐catalytic photoreactivity, this approach expands the toolbox for constructing complex ketoacyl frameworks, offering a concise route toward pharmaceutically relevant motifs.