Identity of the Silyl Ligand in an Iron Silyl Complex Influences Olefin Hydrogenation: An Experimental and Computational Study.

In this study, we explore the selective synthesis of iron silyl complexes using the reaction of an iron mesityl complex (CCC)FeMes(Py) with various hydrosilanes. These resulting iron silyl complexes, (CCC)Fe(SiHPh)(Py)(N), (CCC)Fe(SiMePh)(Py)(N), and (CCC)Fe[SiMe(OSiMe)](Py)(N), serve as effective precatalysts for olefin hydrogenation. The key to their efficiency in catalysis lies in the specific nature of the silyl ligand attached to the iron center.

Synthesis and Characterization of Palladium Pincer Bis(carbene) CCC Complexes.

The metalation of the CCC (CCC = bis(diisopropylphenyl-imidazol-2-ylidene)phenyl) ligand platform with Pd was achieved under mild conditions by reacting [H(CCC)]Cl with Pd(OAc) at room temperature in the presence of 3.1 equiv of LiN(SiMe). The resulting complexes (CCC)PdX (X = Cl or Br) were oxidized by two-electron oxidants PhICl, Br, and BTMABr.

Iron-Catalyzed hydrogen Induced Polarization.

hydrogen induced polarization (PHIP) can address the low sensitivity problem intrinsic to nuclear magnetic resonance spectroscopy. Using a catalyst capable of reacting with hydrogen and substrate in either a hydrogenative or nonhydrogenative manner can result in signal enhancement of the substrate. This work describes the development of a rare example of an iron catalyst capable of reacting with hydrogen to hyperpolarize olefins.

γ-Agostic interactions in (CCC)Fe-Mes(L) complexes.

Agostic interactions were observed in the bound mesityl group in a series of iron compounds bearing a bis(NHC) pincer CCC ligand. The L-type ligand on [(CCC)FeMes(L)] complexes influences the strength of the agostic interaction and is manifested in the upfield shift of the H NMR resonance for the mesityl methyl resonances. The nature of the interaction was further investigated by density functional theory calculations, allowing rationalization of some unexpected trends and proving to be a powerful predictive tool.