Using CS(=O)(=O)Cl, CCOC(=O)CC1OB(O)c2cc(O)cc(Cl)c21 to produce CCOC(=O)CC1OB(O)c2cc(OS(C)(=O)=O)cc(Cl)c21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.