Using CCCC[Sn](CCCC)(CCCC)c1cnccn1, CC(C)(C)OC(=O)c1ccc(Br)cn1 to produce CC(C)(C)OC(=O)c1ccc(-c2cnccn2)cn1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.