Investigating a Redox Active Samarium Complex in Catalytic Reactions

Abstract

Herein the synthesis of a new ethynyl ferrocenyl amidinate ligand [Fc−C≡C‐{C(Ndipp)2H}] (Fc=ferrocenyl; dipp=diisopropylphenyl) and the subsequent formation of the corresponding samarium amido complex [Sm{Fc−C≡C‐[C(Ndipp)2]}2{N(SiMe3)2}] is reported. [Fc−C≡C‐{C(Ndipp)2H}] and [Sm{Fc−C≡C‐[C(Ndipp)2]}2{N(SiMe3)2}] were fully characterized including the study of the complex’ redox properties by cyclovoltammetry. Furthermore, we investigated the catalytic properties of the samarium complex in the intramolecular hydroamination reaction and intermolecular dehydrocoupling of pinacol borane with various amines.

Constrained Geometry ansa‐Half‐Sandwich Complexes of Magnesium – Versatile s‐Block Catalysts

“…twice the reaction time to attain similar conversions, and by far the best performance for a magnesium catalyst [26–29] . After these promising results, we choose to expand the substrate scope and investigate the intermolecular dehydrocoupling of amines with pinacolborane, for which only few metal catalysts have been reported so far [61–68] . Since it is well known that such reaction can also occur without any catalyst in some cases, [69] we carried out control experiments with pinacolborane and the corresponding amines in the absence of any metal catalyst.…”

“…[26][27][28][29] After these promising results, we choose to expand the substrate scope and investigate the intermolecular dehydrocoupling of amines with pinacolborane, for which only few metal catalysts have been reported so far. [61][62][63][64][65][66][67][68] Since it is well known that such reaction can also occur without any catalyst in some cases, [69] we carried out control experiments with pinacolborane and the corresponding amines in the absence of any metal catalyst. Pinacolborane and tert-butylamine respectively pyrrolidine were stirred in dme at room temperature for 1 h, whereupon ~20 % of the respective dehydrocoupling products were observed by 11 B NMR spectroscopy.…”

Investigation of the Coordination Chemistry of a Bisamidinate Ferrocene Ligand with Cu, Ag, and Au

“…Surprisingly, the combination of ferrocene as a versatile ligand scaffold and amidinates, which are a widely used class of ligands for almost all metals of the periodic table ranging from Li to Np, − is strongly underdeveloped. Only a few compounds have been reported with amidinate-functionalized ferrocenes so far, and even fewer with disubstituted ferrocenes. ,− In coinage metal chemistry, amidinates tend to coordinate in a metal bridging mode, forming an {(amidinate)­M 2 (amidinate)} metal core (Figure , left) if weakly bound leaving groups are coordinated to the metal precursor. Otherwise, a κ 1 -structural motif is seen (Figure , right).…”