Using [Br-], CC(C)(C)OC(=O)N1CC(O)(c2ccc([Si](C)(C)C)cc2)C1 to produce CC(C)(C)OC(=O)N1CC(O)(c2ccc(Br)cc2)C1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.