Glycidyl Silanes Enable Regioselective Hydrosilylation of Internal Propargyl Alcohols and Direct Transformation into Activated Silanes for Further Chemical Transformation

Herein, we develop glycidyl silanes to facilitate highly regioselective hydrosilylation of internal propargyl alcohols, the products of which can in turn be converted to synthetically useful fluorosilanes for further chemical transfor-mations under mild conditions. Structure–selectivity studies and density functional theory calculations are consistent with high regioselectivity arising from a critical intermolecular hydrogen bond between the glycidyl and propargylic hydroxy groups. A broad substrate scope illustrates the generality of this reaction to form beta-E silylalkenes. Treatment of the beta-E silylalkenes with a fluoride salt induces simultaneous removal of the glycidyl group and activation of the silane under mild conditions. The fluorosilane products can be converted into vinyl arene and ketone derivatives via Hiyama coupling and Tamao–Fleming oxidation reactions, respectively. The discovery that glycidyl silane improves hydrosilylation regioselectivity and is compatible with expedient silylalkene derivatization may prove applicable to a variety of similar alkyne hydrofunctionalization reactions.