The metal complex catalyzed reactions of anils. I. The reaction of acetone with anilines

Abstract

It has been shown that the formation of anils from anilines and aliphatic ketones is homogeneously catalyzed by a variety of metal complexes. The products of the reactions have been unambiguously identified by preparing the anils using other synthetic routes. The catalysis is quite general and the system is therefore suitable for a systematic catalytic study varying both the catalysts and the substrates. The related reactions of anil hydrolysis and transimination may also be studied. The catalysts used, thiourea complexes of Co(II), Ni(II), and Zn(II), vary in their effectiveness by more than two orders of magnitude. In the present paper experiments defining the catalytic system are described. The equilibrium constants for the complexation of all the substrate molecules have been determined. Qualitative rate data on various ligand exchange and proton transfer steps is presented to demonstrate that such reactions cannot be rate determining in the overall catalytic reactions.