中文摘要：

We report a general and highly efficient Mukaiyama-aldol reaction of ketones and difluoroenoxysilanes.While the reaction of aryl ketones worked efficiently in the presence of Bi（OTf）3, that of aliphatic ketones required the use of Sc（OTf）3. In addition, Sc（OTf）3 was capable of achieving excellent 1,2-selectivity in the corresponding reaction of α,β-unsaturated ketones. This method provides a facile access to differently substituted β-hydroxy α,α-difluoro ketones, versatile synthons for difluomethylated tertiary alcohols.