[{"from": "human", "value": "Please suggest some possible reagents that could have been used in the following chemical reaction. [C][O][C][=C][C][Branch1][C][Br][=C][C][Branch1][Ring1][C][=O][=C][Ring1][=Branch2][O][C]>>[C][O][C][=C][C][Branch1][C][Br][=C][C][Branch1][Ring1][C][O][=C][Ring1][=Branch2][O][C]"}, {"from": "gpt", "value": "[C][C][C][O][C][Ring1][Branch1].[C][C][O].[Cl].[BH4-1].[Na+1]"}]