Using COc1c(CBr)cc(C)cc1CBr, CN1CCNCCN(C)CC1 to produce COc1c(CN2CCN(C)CCN(C)CC2)cc(C)cc1CN1CCN(C)CCN(C)CC1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.