Using CCCC[Sn](CCCC)(CCCC)c1cccc(-c2cccnc2)c1, Clc1ccn2c(Br)cnc2c1 to produce Clc1ccn2c(-c3cccc(-c4cccnc4)c3)cnc2c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.