Phenylethynyl trifluoromethyl sulfone

Alternate Name phenyl(trifluoromethanesulfonyl)acetylene phenylethynyl trifluoromethyl sulfone. 

Cycloaddition Reactions. The trifluoromethylsulfonyl group is a powerful electron withdrawing substituent. Consequently, acetylenic trifluoromethyl sulfones (triflones) are activated toward reactions typical of electron deficient alkynes. Treatment of phenylethynyl trifluoromethyl sulfone (1) with conjugated dienes results in facile Ehels-Alder cycloaddition. Cyclopentadi-ene, 1,3-cyclohexadiene (eq 1), and 1,3-diphenylisobenzofuran, aU give the reaction in good yield. 

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