Decarboxylative aldol reaction of α,α-difluoro-β-keto acids and isatins: A facile synthesis of 3-difluoroalkyl-3-hydroxyoxindole derivatives

The decarboxylative aldol reaction of α,α-difluoro-β-keto acids and unprotected isatins under catalyst- and base-free conditions has been developed. This method is operationally convenient under simple conditions using low-cost readily available raw materials, and therefore could serve as an attractive strategy for the synthesis of 3-difluoroalkyl-3‑hydroxy-2-oxindole derivatives with potential biological activities in moderate to excellent yields.