[{"from": "human", "value": "From the provided chemical reaction, propose some possible reagents that could have been used. [O][=C][Branch1][Ring2][C][C][Br][C][=C][C][=C][Branch1][C][Br][C][=C][Ring1][#Branch1]>>[O][C][Branch1][Ring2][C][C][Br][C][=C][C][=C][Branch1][C][Br][C][=C][Ring1][#Branch1]"}, {"from": "gpt", "value": "[C][O].[Cl].[BH4-1].[Na+1]"}]