Using C=CC[Sn](CCCC)(CCCC)CCCC, CC(C)Cn1c2ccccc2c2cc(-c3ccc4c(c3)c3cc(Br)ccc3n4CC(C)C)ccc21 to produce C=CCc1ccc2c(c1)c1cc(-c3ccc4c(c3)c3ccccc3n4CC(C)C)ccc1n2CC(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.