Base-free O-difluoromethylation of 1,3-diones with difluorocarbene

The base-free O-difluoromethylation of 1,3-diones with difluorocarbene generated from difluoromethylene phosphobetaine (Ph3P+CF2CO2−) is described. The convenient reactions proceeded smoothly to give difluoromethyl enol ethers in moderate to good yields.