Visible-Light Photoredox Synthesis of Chroman-4-ones from Sulfoxonium Ylides

Organic chroman-4-ones are valuable structural motifs, yet many existing synthetic routes rely on harsh conditions or generate toxic byproducts. Here we report a mild and environmentally compatible visible-light method that employs sulfoxonium ylides as α-carbonyl radical precursors. The reaction proceeds through photoredox activation combined with a radical propagation pathway, enabling efficient radical cascade cyclization with 2-(allyloxy)benzaldehydes. This protocol avoids unstable halogenated reagents, produces only benign byproducts, and provides broad access to chroman-4-one derivatives under ambient conditions.