Using COC(=O)c1cccc(S)c1, FC(F)(F)C(F)(I)C(F)(F)F to produce COC(=O)c1cccc(SC(F)(C(F)(F)F)C(F)(F)F)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.