The catalytic Mannich reaction of 1,1-difluoro-2-trialkyl(aryl)silyl-2- trimethyl-silyloxyethenes: Preparation of β-amino acid derivatives

Catalytic Mannich reactions of 1,1-difluoro-2-trialkyl(aryl)-silyl-2- trimethylsilyloxyethenes (3) with a variety of sulfonylimines were utilized for the preparation of α,α-difluoro-β-amino acid derivatives (7). The influence of the Lewis acid on the reaction was examined. Methods for the conversion of α,α-difluoroacylsilanes to α,α- difluorocarboxylic acids were also explored.