Gold-catalyzed thioetherification of allyl, benzyl, and propargyl phosphates

Abstract

Gold-catalyzed thioetherification of C(sp³)–O bonds is described. The reaction of allyl phosphates and thiosilanes in the presence of gold nanoparticles supported on ZrO₂ proceeded efficiently under mild reaction conditions to give the corresponding allyl sulfides in excellent yields. ZrO₂-Supported gold nanoparticles showed excellent catalytic turnover and reusability. In addition, the C–O bonds of benzyl and propargyl phosphates underwent thioetherification to afford benzyl and propargyl sulfides. The reaction of an optically active benzyl phosphate proceeded with excellent chirality transfer to give a benzyl sulfide with high enantiomeric purity. Control experiments corroborated that soluble gold species were responsible for the efficient thioetherification of C–O bonds of phosphates, and characterization of the catalysts revealed that cationic gold species at the surface of gold nanoparticles supported on ZrO₂ served as a source for highly active catalytic species.