Facile Synthesis of Trifluoromethyl-substituted Enynes: Remarkable Reactivity and Stereoselectivity of Tributyl(3,3,3-trifluoropropynyl)stannane in Carbostannylation of Alkynes

Carbostannylation of alkynes with tributyl(3,3,3-trifluoropropynyl)stannane is found to proceed at room temperature in a syn-manner, giving rise to the corresponding CF3-substituted enynes as a single stereoisomer in good yields. Both terminal and, CF3- or RO2C-substituted internal alkynes are applicable to the addition reaction. Synthetic applications of the adduct are also demonstrated.