General Cascade Esterification-Pentafluorosulfanyloxylation of Carboxylic Acids with Cyclic Ethers using Silver Pentafluorooxosulfate.

As the analog of the trifluoromethoxy (OCF3) group, the pentafluorosulfanyloxy group (OSF5) exhibits comparable electronic properties and unique geometry. Previous research has primarily focused on pentafluorosulfanyloxylation of aryl-based substrates; however, a similar transformation in alkyl substrates is exceedingly rare. In this work, we report the first cascade esterification of carboxylic acids with cyclic ethers to achieve the selective synthesis of alkyl-OSF5 products. In this transformation, AgOSF5 serves as the pentafluorosulfanyloxide source, cyclic ethers act as the coupling partners, and the acyl bromide is generated from carboxylic acids. This method tolerates a broad range of carboxylic acids and cyclic ethers, delivering excellent functional group compatibility and consistently high yields.