Tributyltin trifluoromethanesulfonate

White to light beige crystals and chunks

Tri-n-butyltin Trifluoromethanesulfonate is a powerful stannylating reagent. It readily stannylates vinylcuprates and vinylaluminum compounds; catalyzes hydrostannation of aldehydes and ketones by tin hydrides.

Tribuyltin trifluoromethanesulfonate is prepared from Bis(tri-n-butyltin) Oxide and either Trifluoromethanesulfonic Acid (with subsequent removal of water) or Trifluoromethanesulfonic Anhydride, as in eq 1.

The following procedure is quite convenient: freshly distilled trifluoromethanesulfonic anhydride is caused to react with an equal molar amount of tributyltin oxide cooled at 20 °C under nitrogen. When the exothermic reaction completely subsides, the flask is set up for a short-path distillation and the resulting red oil is distilled at about 0.1 mmHg. The distillate is collected without cooling to prevent crystallization of the product in the condenser. Alternatively, this reagent can be prepared in situ by the action of trifluoromethanesulfonic acid on Tri-n-butylstannane in benzene or dichloroethane.

Tribuyltin trifluoromethanesulfonate is deliquescent. Therefore it is best handled as a solution in benzene, ether, or hexane, stored at room temperature under nitrogen. Solutions can be dried with 4 molecular sieves. As with certain other trialkyltin electrophiles, tributyltin trifluoromethanesulfonate is foul smelling. The toxicity of this class of compounds has been described. Use in a fume hood.