Using CN(C(=O)OC(C)(C)C)C1CCC(=O)CC1, FC(F)(Br)Br to produce CN(C(=O)OC(C)(C)C)C1CCC(=C(F)F)CC1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.