Using CCCBr, Cn1cc(-c2cn(COCC[Si](C)(C)C)c3ncc(O)cc23)cn1 to produce CCCOc1cnc2c(c1)c(-c1cnn(C)c1)cn2COCC[Si](C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.