Using C[Sn](C)(C)c1cnc2c(c1)OCC(=O)N2, [Li]N([Si](C)(C)C)[Si](C)(C)C to produce CN1C(=O)COc2cc([Sn](C)(C)C)cnc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.