Highly fluorinated 2,3-dihydro-1,3,4-thiadiazole derivatives via [3+2]-cycloadditions of tertiary thioamides with nitrile imines derived from trifluoroacetonitrile

摘要: Abstract Fluorine-rich 1,3,4-thiadiazole derivatives were prepared by 1,3-dipolar cycloaddition of the in situ generated N-aryl-trifluoroacetonitrile imines with tertiary polyfluoroalkanethioamides (N,N-dialkyl thioamides). Reactions performed under mild conditions THF solutions at room temperature. The formed a fully regioselective manner high yields. In competition experiment, non-fluorinated 1-(morpholin-4-yl)ethanethione was shown to be more reactive towards model nitrile imine than its 2,2,2-trifluoromethylated analogue.