Internally reuse by-product as promoter: A catalyst-free imine formation/Mukaiyama-Mannich sequence of α-amido sulfones with fluorinated silyl enol ethers

Described herein is a catalyst-free tandem imine formation/Mukaiyama-Mannich sequence of fluorinated silyl enol ethers and alpha-amido sulfones, allowing the efficient synthesis of value-added beta-amino alpha-fluorinated ketones in good to excellent yields. Noticeably, the key for high efficacy of the catalyst-free reaction is attributed to the in situ generated acidic by-product PhSO2X (X = TMS or H) that can act as an promoter for the subsequent Mukaiyama-Mannich reaction.