Light-driven C–O coupling of carboxylic acids and alkyl halides over a Ni single-atom catalyst

Although visible-light-driven dual photoredox catalysis, a method that combines photoabsorbers and transition metals, has become a powerful tool to conduct coupling reactions, resource economical and scalability issues persist, owing to the use of catalysts and light absorbers that exploit critical raw materials (such as iridium complexes), and are homogeneous in nature. Here we report the merger of metallic single-atom and photoredox catalysis, in the form of a Ni atom-supported carbon nitride material, for the C–O coupling of carboxylic acids and alkyl halides. This operationally straightforward system, composed of only earth-abundant components, exhibits a wide functional group tolerance. Additionally, short reaction times, facile recovery and high catalyst stability make this method highly attractive for industrial applications. Visible-light-driven dual photoredox catalysis often uses expensive metals, such as iridium. Now, a photocatalytic approach using a Ni single-atom carbon nitride catalyst is reported for the C–O cross-coupling of carboxylic acids and alkyl halides, demonstrating broad functional group tolerance, short reaction times, facile recovery and excellent stability.