Using OC(c1ccccc1)(c1ccc(Br)cc1)C(c1ccccc1)c1ccccc1 to produce Brc1ccc(C(=C(c2ccccc2)c2ccccc2)c2ccccc2)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.