Using CCCC[Sn](CCCC)(CCCC)c1ncccn1, CCOC(=O)c1sc(Br)nc1C(F)(F)F to produce CCOC(=O)c1sc(-c2ncccn2)nc1C(F)(F)F, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.