Metal-to-Ligand Alkyl Migration Inducing Carbon-Sulfur Bond Cleavage in Dialkyl YIII Complexes Supported by Thiazole Containing Amidopyridinate Ligands

Much of the current interest in organometallic chemistry is linked to the academic and industrial quest for novel types of efficient and selective homogeneous catalysts. For the target of improving the catalyst's performance, a precise control of the metal coordination sphere is desired; this is commonly accomplished by a fine tuning of the steric and electronic properties of the ancillary ligands. Highly electrophilic lanthanide metal ions in combination with pyridylamido ligands are the basis of nonconventional, highly efficient and selective catalyst precursors of great promise for polyolefin production and hydroamination reactions. Recent studies from our groups have unveiled the wealthy organometallic chemistry of these nitrogen-based systems, highlighting at the same time their unique structure-activity relationship. Herein, we describe the synthesis and characterization of a new family of YIII dialkyl complexes stabilized by tridentate {N-,N,N} monoanionic methylthiazole- or benzothiazoleamidopyridinate ligands. An in-depth evaluation of the stability of the dialkyl species along with the reactivity of the respective YIII-Csp2 and YIII-Csp3 bonds in the presence of selected protic reagents have shown the occurrence of novel and somehow unpredictable reaction paths on the benzothiazolecontaining complexes.