Using C[C@H](C=O)[C@H]1CC[C@H]2[C@@H](O[Si](C)(C)C(C)(C)C)CCC[C@]12C, BrC(Br)(Br)Br to produce C[C@H](C=C(Br)Br)[C@H]1CC[C@H]2[C@@H](O[Si](C)(C)C(C)(C)C)CCC[C@]12C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.