Using C[Sn](C)(C)C, COC(=O)c1nc(Br)c2nc(-c3ccccc3)oc2c1O to produce COC(=O)c1nc(C)c2nc(-c3ccccc3)oc2c1O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.