Using C[Sn](C)(C)C1=CCC2(CC1)OCCO2, COCC1CN(c2ccc(Br)cn2)C(=O)O1 to produce COCC1CN(c2ccc(C3=CCC4(CC3)OCCO4)cn2)C(=O)O1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.