The tungsten alkylidyne [CF3-ONO]W=CC(CH3)(3)(THF)(2) (3) {where CF3-ONO = (MeC6H3[C(CF3)(2)O])(2)N-3} supported by a trianionic pincer-type ligand demonstrates enhanced nucleophilicity in unusually fast Wittig-like reactions. Experiments are designed to provide support for an inorganic enamine effect that is the origin of the enhanced nucleophilicity. Treating complex 3 with various carbonyl-containing substrates provides tungsten-oxo-vinyl complexes upon oxygen atom transfer. The rates of reactivity of 3 are compared with the known alkylidyne (DIPP)(3)W=CC(CH3)(3) (DIPP = 2,6-diisopropylphenoxide). In all cases (except acetone), complex 3 exhibits significantly faster overall rates than (DIPP)(3)W=CC(CH3)(3). New oxo-vinyl complexes are characterized by NMR, combustion analysis and single crystal X-ray diffraction. Treating 3 with acid chlorides provides the tungsten oxo chloride species [CF3-ONO]W(O)Cl (4) and disubstituted alkynes. In the case of acetone the oxo-vinyl complex results in two rotational isomers 10(syn) and 10(anti). The rate of isomerization was determined for the forward and reverse directions and was complimented with DFT calculations.