Using C=CCBr, C[C@H](C[C@H](O)[C@H](Cc1ccccc1)NC(=O)c1cc(O)cc(N2CCCC2=O)c1)C(=O)NCCC(C)(C)C to produce C=CCOc1cc(C(=O)N[C@@H](Cc2ccccc2)[C@@H](O)C[C@@H](C)C(=O)NCCC(C)(C)C)cc(N2CCCC2=O)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.