Pyrazolylborate-zinc alkoxide complexes. 3. Acid-base reactions

The alkoxides Tp(Ph,Me)Zn-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 beta- and gamma-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-beta-ketoiminate.