Synthesis of Tertiary Fluorides through an Acid-Mediated Deoxyfluorination of Tertiary Alcohols

J Org Chem. 2023 Oct 20;88(20):14527-14539. doi: 10.1021/acs.joc.3c01558. Epub 2023 Sep 28.

Abstract

The combination of methanesulfonic acid and potassium bifluoride is reported for the deoxyfluorination of tertiary alcohols. Under metal-free conditions that use readily available, cheap, and easy-to-handle reagents, a range of tertiary alcohols could be converted into the corresponding fluorides in excellent yields (average yields of 85% for 23 examples). Mechanistic investigation showed that the reaction proceeds at 0 °C, in part, through an elimination/hydrofluorination pathway, but no residual alkenes are observed. The application of these conditions for the fluorination of ether and ester is also demonstrated.