Using BrC(Br)(Br)Br, O=CCOc1ccc(Oc2cccc(Cl)c2)cc1Br to produce Clc1cccc(Oc2ccc(OCC=C(Br)Br)c(Br)c2)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.