Using CC(C)(C)C[Ta+2](CC(C)(C)C)CC(C)(C)C, [Li]CC(C)(C)C to produce CC(C)(C)C=[Ta](CC(C)(C)C)(CC(C)(C)C)CC(C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.