A highly efficient room temperature non-organometallic route for the synthesis of α,β,β-trifluorostyrenes by dehydrohalogenation

Various 1-aryl-1,2,2,2-tetrafluoroethanes (ArCHFCF3, Ar=phenyl, substituted phenyl, naphthyl, heteroaryl) were synthesized by the fluorination of the corresponding alcohols with DAST. Dehydrofluorination of ArCHFCF3 using lithium hexamethyldisilazide (LHMDS) base in THF at room temperature produced 1,2,2-trifluorostyrenes (ArCF=CF2) in 61–91% isolated yields. This procedure provides an excellent non-organometallic alternative to the generally used metallation-Pd(0) coupling methods.