Trisaminosulfonium salts of the formula (R.sup.1 R.sup.2 N)(R.sup.3 R.sup.4 N)(R.sup.5 R.sup.6 N)S.sup.+ X.sup.- wherein the R groups are alkyl of 1-20 carbons and each alkyl has at least 2 alpha hydrogens and X is selected from the group (CH.sub.3).sub.3 SiF.sub.2, Cl, Br, I, CN, NCO, NCS NO.sub.2 and N.sub.3, are soluble in organic liquids. They are useful as polymerization catalysts and as reagents to replace other atoms or groups in organic compounds with F, Cl, Br, I, CN, NCO, NCS, NO.sub.2 or N.sub.3.