Using C=C(OCC)[Sn](CCCC)(CCCC)CCCC, COC(=O)c1cc(Br)cn1-c1ncccc1Cl to produce COC(=O)c1cc(C(C)=O)cn1-c1ncccc1Cl, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.