Using CC(C)(C)c1cc(Br)cc(Br)c1, C=C(OCC)[Sn](CCCC)(CCCC)CCCC to produce CC(=O)c1cc(Br)cc(C(C)(C)C)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.