Using C=CCBr, COC(=O)C[C@H](NC(=O)OC(C)(C)C)C(=O)N1CCCC1 to produce C=CC[C@H](C(=O)OC)[C@H](NC(=O)OC(C)(C)C)C(=O)N1CCCC1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.