Chemodivergent Synthesis of Oxazolidin-2-ones via Cu-Catalyzed Carboxyl Transfer Annulation of Propiolic Acids with Amines.

Carboxylic acids are widely found in natural products and bioactive molecules and have served as raw material compounds in industry. We now report the first example of copper(I)-catalyzed carboxyl transfer annulation of propiolic acids with amines, thereby chemodivergently constructing the oxazolidine-2-ones. In this reaction, two kinds of key propargyamine intermediates were formed through sequential CuI/NBS-catalyzed oxidative deamination/decarboxylative alkynylation or CuI-catalyzed decarboxylative hydroamination/alkynylation. The advantages of this decarboxylative coupling/carboxylative cyclization are showcased in the atom economy, chemical specificity, and functional group tolerance.