Using CC(C)(C)OC(=O)NOC(=O)OC(C)(C)C, COc1ccc(SCCC(=O)O)cc1 to produce COc1ccc(SCCC(=O)N(OC(=O)OC(C)(C)C)C(=O)OC(C)(C)C)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.