Using O=Cc1cc(Br)cc(Br)c1, CCOP(=O)(OCC)C(c1ccccc1)c1ccccc1 to produce Brc1cc(Br)cc(C=C(c2ccccc2)c2ccccc2)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.