Yang, Liangru Krüger, Anneke Neels, Antonia Albrecht, Martin 2008-05-28 Direct metalation of C2-protected diimidozolium salts with RhCl₃ or [RhCl(cod)]₂ and KI afforded a series of new rhodium(III) complexes with abnormally C4-bound, <i>cis</i>-chelating NHC ligands. The complexes were isolated as dimetallic species containing two (μ²-I)₃-bridged rhodium(III) centers. In the presence of coordinating ligands such as CH₃CN, PPh₃, or dppe, the dimeric structure is readily cleaved and yields monometallic complexes. Crystallographic analysis of representative structures indicates a higher <i>trans</i> influence of abnormally C4-bound carbenes as compared to normal NHCs. The exceptionally strong donor ability of carbenes in such a C4 coordination mode increases the catalytic activity of the rhodium center and allows for efficient transfer hydrogenation of ketones in <i>i</i>PrOH/KOH. application/pdf https://folia.unifr.ch/global/documents/300815 https://folia.unifr.ch/documents/300815/files/albrecht_rcc.pdf https://folia.unifr.ch/documents/300815/files/albrecht_rcc_sm.CIF eng info:eu-repo/semantics/altIdentifier/doi/10.1021/om800110c info:eu-repo/semantics/openAccess License undefined Organometallics. - 2008, vol. 27, no. 13, p. 3161–3171 info:eu-repo/classification/udc/54 Rhodium(iii) complexes containing C4-bound N-heterocyclic carbenes: synthesis, coordination chemistry, and catalytic activity in transfer hydrogenation http://purl.org/coar/resource_type/c_6501