Iron-Photocatalyzed Decarboxylative Coupling Reaction of Carboxylic Acids with Alkynyl Bromides

A green and efficient iron-metal photocatalytic decarboxylative alkynylation reaction of carboxylic acids with alkynyl bromides was developed. Employing commercially available Fe(OTf)₃ as the catalyst and CH₃CN as the reaction solvent, the reaction proceeds at room temperature with 390 nm irradiation, affording the decarboxylated alkynylation products in high yields with Cs₂CO₃ as a base. This method is notable for its operational simplicity, environmentally friendly features, and broad substrate scope. It accommodates structurally diverse carboxylic acids, including α-amino acids, dipeptides, aliphatic and α-oxygenated acids, and complex pharmaceutical acids, highlighting its potential for synthetic and medicinal chemistry applications.