Metal-Free Iodine-Catalyzed Oxidation of Ynamides and Diaryl Acetylenes into 1,2-Diketo Compounds

J Org Chem. 2018 Apr 20;83(8):4703-4711. doi: 10.1021/acs.joc.8b00484. Epub 2018 Apr 4.

Abstract

Metal-free oxidation of ynamides is described, employing pyridine- N-oxides as oxidants under molecular iodine catalysis. In stark contrast to Brønsted acid catalysis, iodophilic activation of ynamides diverts the reaction manifold into a dioxygenation pathway. This oxidation is very rapid at room temperature with only 2.5 mol % I2. Furthermore, this protocol could be extended to nonactivated alkynes, such as diarylacetylenes, to deliver various benzil derivatives.

Publication types

  • Research Support, Non-U.S. Gov't