Upon rapid injection, a variety of thiocarbonyl compounds react with the Gilman reagent Me2CuLi at -100 degrees C inside the probe of an NMR spectrometer to give high yields of complexes. Typical examples of substrates include carbon disulfide, methyl dithio-acetate, methyl dithiobenzoate, thiobenzophenone, ethylene trithiocarbonate, and phenyl isothiocyanate. Evidence suggesting the formal oxidation state of copper in these complexes to be CO is presented. The last example was particularly interesting, since it involved a transient intermediate that was identified as a complex with a C-N double bond. Methyl isothiocyanate gave a stable C-N double-bond complex.