Comparison of α- and β-trifluoromethylsubstituted acrylic acids in their reactions with thiols
α-(Trifluoromethyl)acrylic acid (1) and γ,γ,γ-trifluorocrotonic acid (2) add AcSH (exothermally and at 100 °C, respectively) in the absence of a catalyst to form products of β-thiolation, which can be easily hydrolyzed to the corresponding β-mercaptoalkanoic acids. Thiols also add regiospecifically to acids1 (in the absence of a catalyst) and2 only in the presence of trifluoromethanesulfonic acid as the catalyst) when heated.
Key wordsα-(trifluoromethyl)acrylic acid, γ,γ,γ-trifluorocrotonic acid, thiolacetic acid thiols, thiolation
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