Pyrazolylborate−Zinc Alkoxide Complexes. 3. Acid−Base Reactions

The alkoxides TpPh,MeZn−OR (R = Me, Et, i-Pr) undergo acid−base reactions with all hydrogen compounds whose
acidity is higher than that of the corresponding alcohol ROH. Thus, anion exchange occurs with the common acids
acetic acid, acetohydroxamic acid, acetylacetone, phenol, and ethylmercaptan. Alkoxide exchange is observed
using methanol, ethanol, and trifluoroethanol. With the NH acids cyanamide, trifluoroacetamide, and pyrazoles, the
corresponding anions are attached to zinc, and likewise β- and γ-lactams, a thiazolidinedione, and the cyclic
sulfimide saccharin are deprotonated. Of the CH acids acetonitrile forms the Tp*Zn−cyanomethanide. Acetone is
deprotonated by the cyanomethanide complex and incorporated as the Tp*Zn−β-ketoiminate.