Carbon-Carbon Bond Formation of Trifluoroacetyl Amides with Grignard Reagents via C(O)-CF3 Bond Cleavage.

The reaction of trifluoroacetyl amides with Grignard reagent for the substitution of CF3 group with various alkyl or aryl groups is described. A variety of aryl, quinolin-8-yl, and (hetero)alkyl functional groups as well as F, Cl, and Br atoms are well tolerated. These moisture-stable and easily available trifluoroacetyl amides can be conveniently obtained and used as new versatile precursors for isocyanates. The control experiments show that the reaction proceeds via an isocyanate intermediate and/or alkoxide/amide dual anionic intermediate.