Bifluoride salt reported by
K. Barry Sharpless and colleagues as a powerful catalyst for the sulfur(VI) fluoride exchange (
SuFEx) reaction between aryl silyl ethers and aryl fluorosulfates or alkyl sulfonyl fluorides. Superior to organosuperbases DBU and BEMP, tris(dimethylamino)sulfonium bifluoride enables low catalyst loading (0.05 mol%) for preparation of polysulfates and polysulfonates with high molecular weight and narrow polydispersity. Reaction is amenable to scale up.