Sulfur Ylides in Skeletal‐Editing—Ring Expansion Reactions

ABSTRACT Sulfur ylides (S‐ylides) have long been recognized as versatile reagents and intermediates in organic synthesis. In particular, their role as surrogates for diazo compounds has recently gained considerable attention due to their superior stability, safer handling, and broader functional group tolerance, which make them attractive alternatives in both academic and industrial settings. Beyond classical transformations, S‐ylides have been increasingly applied in skeletal‐editing strategies, such as ring expansion reactions, that provide access to pharmaceutically relevant frameworks. Despite these advances, challenges remain in developing highly enantioselective catalytic protocols and expanding the scope of sustainable photochemical methodologies. This perspective highlights the emerging potential of S‐ylides in skeletal editing, tracing their evolution from fundamental studies to state‐of‐the‐art applications, while offering insights into current limitations and future opportunities that could reshape their role in synthetic chemistry.