Fluorinated 2,6-Xylenesulfonyl Group: A Protective Group for Amines

We have developed a fluorinated 2,6-xylenesulfonyl group (fluorinated xysyl, ^fXs) as a protective group for amines. The sulfonyl group could be attached to amines by reactions with the corresponding sulfonyl chloride, and survived various conditions, including acidic, basic, and even reductive conditions. The ^fXs group could be cleaved by treatment with a thiolate under mild conditions.