Using O=C1CCC(=O)O1, CC(C)(C)[Si](C)(C)Oc1cccc(Br)c1 to produce CC(C)(C)[Si](C)(C)Oc1cccc(C(=O)CCC(=O)O)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.