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.

Metal complex catalyzed reactions of anils. II. Transimination

“…The preparation and purification of the reagents and catalysts used in these studies have been described previously (1).…”

Outer sphere complexes as intermediates in coordination chemistry

“…The ligand exchange reactions of related complexes of Ni(II) and Zn(II) were also studied [83,84] an.d it seems probable that the mechanisms are similar. These thiourea complexes are effective catalysts for a variety of anil formation and transimination reactions [85][86][87][88]. A kinetic study demonstrated that in anil formation, for example, both the aniline and the ketone were associated with the catalytically active metal complex during the rate determining step [86].…”