Using CCCCBr, O[C@@](CS)(Cn1ccnc1)c1ccc(Cl)cc1Cl to produce CCCCSC[C@](O)(Cn1ccnc1)c1ccc(Cl)cc1Cl, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.