Using O=C1OC(Br)c2ccccc21, C[C@@H](O)[C@H]1C(=O)N2C(C(=O)[O-])=C(S/C=C\c3scnc3CO)[C@H](C)[C@H]12 to produce C[C@@H](O)[C@H]1C(=O)N2C(C(=O)OC3OC(=O)c4ccccc43)=C(S/C=C\c3scnc3CO)[C@H](C)[C@H]12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.