Unusual Rearrangement-Remercuration Reactions of Allylic Silanols.

We present the first examples of rearrangement reactions of allylic silanol substrates into linear ketone and 5-membered cyclic silanediol organomercurial products. Both reactions are mediated by Hg(OTf)2 but differ in the use of base, solvent, and temperature. The substrate scope of both transformations was explored, and the product organomercurials were shown to be valuable synthons. Mechanistic studies suggest that both products are the result of a series of transformations, cascading in one pot. DFT analysis provides a basis for understanding the rearrangement of a 6-endo intermediate into the 5-exo cyclic silanediol product.