[{"from": "human", "value": "Please propose potential reagents that might have been utilized in the provided chemical reaction. [C][O][C][=C][C][Branch1][C][Br][=C][C][Branch1][Ring1][O][C][=C][Ring1][=Branch2]>>[O][C][=C][C][Branch1][C][O][=C][C][Branch1][C][Br][=C][Ring1][Branch2]"}, {"from": "gpt", "value": "[Br][B][Branch1][C][Br][Br].[Cl][C][Cl]"}]