Using O=[N+]([O-])c1ccc(Br)cc1C(F)(F)F, C=CC[Sn](CCCC)(CCCC)CCCC to produce C=CCc1ccc([N+](=O)[O-])c(C(F)(F)F)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.