Fluorosulfonate

Fluorosulfonate, in organic chemistry, is a functional group that has the chemical formula F-SO₂-O-R, and typically is a very good leaving group. In inorganic chemistry, fluorosulfonate is another term for fluorosulfate, the anion F-SO₂-O⁻, the conjugated base of fluorosulfonic acid. They form a series of salts with metal and organic cations called fluorosulfates.

Organic (alkyl) fluorosulfonates are usually strong alkylation agents, similar to triflate esters (F₃C-SO₂-OR). But unlike the triflate group, the fluorosulfonate group is not stable against hydrolysis. Therefore, fluorosulfonate esters are less frequently used as alkylation agents than triflate esters.