Tethered Silanoxymercuration of Allylic Alcohols.

We present the first examples of tethered olefin functionalization reactions using a silanol auxiliary. A range of allylic alcohols are readily condensed with di--butylsilyl bis(trifluoromethanesulfonate) to form allylic silanols. When treated with Hg(OTf) and NaHCO, these silanols easily transform into cyclic silanediol organomercurial compounds. In most cases, the reactions are exquisitely diastereoselective. The scale can be increased more than 10-fold without a loss of yield and selectivity. We demonstrate that the silanediols are versatile synthons for a variety of further reactions.