Novel Generation of 3,3,3-Trifluoropropynyllithium and Transformation of the Carbonyl Adducts to Trifluoromethyl-Substituted Allenes

A novel method for the generation of 3,3,3-trifluoro­propynyllithium is reported, which involves treatment of trifluoromethyl-substituted enol tosylate, prepared from 1,1-dichloro-3,3,3-trifluoroacetone, with two equivalents of butyllithium. ­Palladium-catalyzed coupling reaction of sulfonates of the carbonyl adducts with organozinc reagents gave trifluoromethyl-containing tri- and tetrasubstituted allenes.