Using Cc1cc(CO)cc2cn(COCC[Si](C)(C)C)nc12, BrC(Br)(Br)Br to produce Cc1cc(CBr)cc2cn(COCC[Si](C)(C)C)nc12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.