Decarboxylative Alkynylation and Carbonylative Alkynylation of Carboxylic Acids Enabled by Visible‐Light Photoredox Catalysis

Visible‐light‐induced photocatalytic decarboxylative alkynylations of carboxylic acids have been developed for the first time. The reaction features extremely mild conditions, broad substrate scope, and avoids additional oxidants. Importantly, a decarboxylative carbonylative alkynylation has also been carried out in the presence of carbon monoxide (CO) under photocatalytic conditions, which affords valuable ynones in high yields at room temperature.