The transition-metal-catalyzed C−H functionalization of sulfoxonium ylides with alkynes formally participates in [4 + 2] annulations to deliver the naphthol scaffolds. In contrast, herein we disclose the first Rh(III)-catalyzed C−H activation, followed by redox-neutral [3 + 2] annulation of sulfoxonium ylides with 1,3diynes, which delivers the alkynated indenone derivatives. This protocol features a good functional group tolerance, a broad substrate scope, moderate to excellent yields, and mild reaction conditions. The reaction mechanism was supported through ESI-HRMS by characterizing key intermediates in the catalytic cycle.

Transition metal‐catalyzed C−H functionalization of diverse arenes with alkyne units has attracted enormous attention for decades since they provide straightforward access to various functionalization/annulations, which are commonly present in bioactive compounds and natural products. Recently, conjugated alkynes (1,3‐diynes) have been utilized as key coupling partner in many C−H activation reactions due to their versatile characteristic properties. The presence of two C≡C bonds in conjugated 1,3‐diyne brings the new diversity in synthetic transformations, such as chemo‐, regioselective pathways, mono‐bis functionalizations, cascade annulations, etc. Herein, we summarized the latest developments in the realm of transition‐metal‐catalyzed C−H functionalizations of diverse arenes with 1,3‐diynes. Moreover, we highlighted the diverse transformations, conditions, mechanisms and applications of the corresponding reaction in detail.