INOR 49 |
| Previous studies from our labs have examined synthesis and hydrogen bonding in complexes of hybrid ligands featuring pyrazole and either phosphine- or thioether-containing side chains (J. Org. Chem. 2002, 67, 9200-9209 and Inorg. Chem. 2003, 42, 3347-3355). Here related N-heterocyclic carbenes will be investigated, exploring the predicted superior binding of a carbene ligand in comparison to ligands previously stated. Presented catalysts are capable of intramolecular hydrogen bonding exemplified by a pyrazole N-H group (B).The carbene acts as an ancillary ligand enabling one nitrogen of the pyrazole to chelate and the other nitrogen to perform hydrogen bonding or proton transfer to substrate or metal ligand (HX or X). Synthetic routes to imidazol-2-ylidene precursors and its congruent addition to metals by transmetallation, reversible carboxylation and free carbene to A or B will be discussed. This difference, as well as, methods of synthesis, characterization, and the catalytic utility of the complexes will be presented.
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Organometallic Catalysts
8:30 AM-12:20 PM, Sunday, August 19, 2007 BCEC -- 212, Oral
Division of Inorganic Chemistry |
