Pummerer rearrangement, connective

Acid anhydrides and/or acids are employed in the majority of synthetic applications of the Pummerer reaction. However, there are a number of other reagents which activate the sulfoxide oxygen in the Pummerer reaction. The use of organosilicon reagents is discussed in Sections 4.7.3.3,4.7.3.S and 4.7.3.7 in connection with the preparation of trimethylsiloxy sulfides and vinyl sulfides. Recently it was shown that the trimethylsilyl ester of polyphosphoric acid also promotes the Pummerer rearrangement. 

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