Recent studies in asymmetric catalysis using ferrocenyl ligands

Abstract

Chiral bidentate ferrocenyl ligands have been fined-tuned in terms of their steric and electronic properties, and thus adapted to a variety of reactions catalyzed by transition metals. The position of the two ligating units (two different PR2 groups, two pyrazolyl, or a combi- nation thereof) attached to the ferrocenylethyl fragment may be interchanged. A comparison of P,N-ligands with their corresponding inversed (N,P) counterpart is presented for the Pd-catalyzed allylic amination. Dendrimers containing Josiphos-type ligands up to the third generation have been prepared and used in e.g. Rh-catalyzed hydrogenation reactions. The intramolecular Ir- catalyzed hydroamination reaction has been found to require an acidic N-H functionality and the presence of co-catalytic amounts of base. Olefin isomerization was found to be an important competing side-reaction. Kinetic/mechanistic studies of the Pd-catalyzed hydrosilylation of styrenes have been carried out.