Transition-Metal-Free Oxidative Decarboxylative Cross Coupling of α,β-Unsaturated Carboxylic Acids with Cyclic Ethers under Air Conditions: Mild Synthesis of α-Oxyalkyl Ketones.

A novel K2S2O8-promoted decarboxylative cross coupling of α,β-unsaturated carboxylic acids with cyclic ethers was developed under aerobic conditions. The present protocol, which includes C-C and C═O bond formation in one step through addition, oxidation, and decarboxylation processes, leads to the desired ketone products in moderate to excellent yields. In addition, mechanism studies showed that the transformation process undergoes a radical pathway via a direct activation of the α-sp3 C-H bond of oxygen of the cyclic ether.