Zirconium-Catalyzed Synthesis of 6-(Trifluoromethyl)-2 H-pyran-2-ones via C-C Bond Cleavage

J Org Chem. 2024 Apr 19;89(8):5683-5689. doi: 10.1021/acs.joc.4c00227. Epub 2024 Apr 3.

Abstract

A strategy for the annulation reaction of alkynones with ethyl 4,4,4-trifluoro-3-oxobutanoate through C-C bond cleavage is described. The zirconium-catalyzed transformation provides access to a wide range of structurally diverse 6-(trifluoromethyl)-2H-pyran-2-ones in moderate to good yields, utilizing Na2CO3 as a base. Further transformations into trifluoromethylated arene derivatives have been demonstrated as well. Furthermore, plausible reaction pathways are proposed by conducting various control experiments and isolating a β-diketone intermediate (X-ray) containing an intramolecular hydrogen bond.