Coupling of Carboxylic Acids with Ynamides and Subsequent Rearrangement for the Synthesis of Imides/Amides

A coupling of carboxylic acids with ynamides and subsequent rearrangement for the synthesis of imides and amides is reported. The carboxylic acids could couple with ynamides to form α-acyloxyenamide followed by sulfonyl group migration and Mumm rearrangement to furnish the amides. Additionally, the products could be subjected to further rearrangement to deliver β-keto amides. This metal-free process represents an interesting method for chemical bonds cleavage and regeneration. Furthermore, divergent transformation of products were conducted to deliver an array of compounds.