Reaction of aldimines and difluoroenoxysilane, an unexpected protocol for the synthesis of 2,2-difluoro-3-hydroxy-1-ones

An unexpected reaction of aldimines and difluoroenoxysilane promoted with Zn(OTf)2 was disclosed. The reaction gave the unexpected Mukaiyama-aldol adducts 3 in excellent yields (up to 87%) with the addition of H2O and the corresponding Mannich-type adduct 4 was not observed in this catalytic system.