Using O=C(CCc1cc(I)c(OCc2cccc(I)c2)c(I)c1)OCc1cccc(I)c1 to produce O=C(O)CCc1cc(I)c(OCc2cccc(I)c2)c(I)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.