Mechanochemical Conversion of Aromatic Amines to Aryl Trifluoromethyl Ethers.

Increased interest in the trifluoromethoxy group in organic synthesis and medicinal chemistry has induced a demand for new, selective, general, and faster methods applicable to natural products and highly functionalized compounds at a later stage of hit-to-lead campaigns. Applying pyrylium tetrafluoroborate, we have developed a mechanochemical protocol to selectively substitute the aromatic amino group with the OCF functionality. The scope of our method includes 31 examples of ring-substituted anilines, including amides and sulfonamides. Expected SAr products were obtained in excellent yields. The presented concise method opens a pathway to new chemical spaces for the pharmaceutical industry.