We report excellent reactivity and enantioselectivity of a C2-symmetric copper-bound N-heterocyclic carbene (NHC) in the hydrosilylation of a variety of structurally diverse ketones. This catalyst exhibits extraordinary enantioselctivity in the reduction of such challenging substrates as 2-butanone and 3-hexanone. Even at low catalyst loading (2.0 mol%) the reactions occur in under an hour at room temperature and often do not require purification beyond catalyst and solvent removal. The scope of this transformation was investigated in the reduction of ten aryl-alkyl and alkyl-alkyl ketones.

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Soft X-ray photoelectron spectroscopy has been used to investigate the radiosensitizer nimorazole and related model compounds. We report the valence and C, N, and O 1s photoemission spectra and K-edge NEXAFS spectra of gas-phase nimorazole, 1-methyl-5-nitroimidazole, and 4(5)-nitroimidazole in combination with theoretical calculations. The valence band and core level spectra are in agreement with theory. We determine the equilibrium populations of the two tautomers in 4(5)-nitroimidazole and find a ratio of 1:0.7 at 390 K. The NEXAFS spectra of the studied nitroimidazoles show excellent agreement with spectra of compounds available in the literature that exhibit a similar chemical environment. By comparing 1-methyl-5-nitroimidazole (single tautomer) with 4(5)-nitroimidazole, we are able to disentangle the photoemission and photoabsorption spectra and identify features due to each single tautomer.

Chiral, C2-symmetric imidazolium and imidazolinium ions, as well as the corresponding copper or silver bound carbenoids, have been prepared. Structural study of these compounds by X-ray crystallography reveals a chiral pocket that surrounds the putative carbene site or the metal-carbene bond, at carbon 2, in three of the four ligands prepared. Preliminary investigation into the application of these complexes has shown one of them to be highly enantioselective in the hydrosilylation of acetophenone.

Single crystal X-ray crystallography is the most powerful structural method for the determination of the 3D structures of molecules. While the results of a routine diffraction experiment readily provide unambiguous determination of the relative configuration of all stereogenic centers in the molecule, determination of absolute configuration is more challenging. This chapter provides some helpful tips towards increasing the chances of success in the determination of the absolute configuration of a chiral, enantiomerically pure natural product using X-ray crystallography.