[{"from": "human", "value": "What reagents could have been utilized in the following chemical reaction? [C][O][C][=Branch1][C][=O][C][C][=C][C][=C][Branch1][C][Br][C][=C][Ring1][#Branch1][Cl]>>[O][C][C][C][=C][C][=C][Branch1][C][Br][C][=C][Ring1][#Branch1][Cl]"}, {"from": "gpt", "value": "[C][C][O].[Cl].[O].[BH4-1].[Ca+2].[Cl-1].[Cl-1].[Na+1]"}]