Using C[C@@H](Cc1ccc(O)c(O)c1)N1C[C@@H](c2cccc(Cl)c2)OC1=O, CCOC(=O)C(Br)(Br)C(=O)OCC to produce CCOC(=O)C1(C(=O)OCC)Oc2ccc(C[C@@H](C)N3C[C@H](c4cccc(Cl)c4)OC3=O)cc2O1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.