Photoinduced Protocol for Aerobic Oxidation of Aldehydes to Carboxylic Acids under Mild Conditions

Herein, a green and practical methodology for the synthesis of carboxylic acids from cheap and available aldehydes is demonstrated. Various aldehydes are well compatible, yielding the corresponding carboxylic acids in moderate-to-good yields. This approach features many advantages, including excellent step-efficiency, using molecular oxygen (O-2) as the sole oxidant and water as the main solvent, and performing under room temperature and without any catalyst and additive. Moreover, this strategy not only provides a practical protocol for large-scale synthesis but also can be extended to the facile and efficient synthesis of some valuable compounds such as syringic acid, gemfibrozil, and probenecid, highlighting its application value.