Thioxanthone: A Benchmark Photocatalyst for Organic Synthesis

Abstract Thioxanthone (TX) and its derivatives are standout, heavy‐atom‐free triplet photosensitizers, due to their high triplet energy, long‐lived triplet states, and ability to work synergistically with metal catalysts. These features render them highly useful in photochemical processes. A previous 2021 review covered TX's photophysical properties and photochemical applications. This review constitutes an update and highlights the growing number of studies since then, demonstrating TX's versatility in synthetic organic photochemistry. The content covers the literature during the period 2021–2025 and is organized by reaction type excluding applications in polymerization reactions.