Using COC(=O)N[C@H](C(=O)O)C(C)(C)C, CC[C@H](C)[C@@H](C(=O)N[C@@H](Cc1ccccc1)C[C@H](O)[C@@H](N)Cc1ccccc1)N1CCN(Cc2ccnc3ccccc23)C1=O to produce CCC(C)[C@@H](C(=O)N[C@@H](Cc1ccccc1)C[C@H](O)[C@H](Cc1ccccc1)NC(=O)[C@@H](NC(=O)OC)C(C)(C)C)N1CCN(Cc2ccnc3ccccc23)C1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.