Gold-Catalyzed Addition of Sulfonic Acids to Alkynes to Form Vinyl Sulfonates.

In the presence of a catalytic amount of (Ph3P)AuNO3 and phthalimide, the addition of toluenesulfonic acid or methanesulfonic acid to alkynes has been shown to proceed and gives vinyl tosylates and vinyl mesylates in good yields and regioselectivity.