The next generation of C2-symmetric ligands: A di-N-heterocyclic carbene (NHC) ligand and the synthesis and X-ray characterization of mono- and dinuclear rhodium(I) and iridium(I) complexes

Synthesis and characterization of κ-2-bis-N-heterocyclic carbene rhodium(I) catalysts: Application in enantioselective arylboronic acid addition to cyclohex-2-enones

“…In particular, four isopropyl methyl resonances appear at 22.5, 23.6, 23.9, and 25.4 ppm and the corresponding methines resonate at 54.9 and 52.1 ppm. The carbene carbons resonate as doublets (J ¼ 53 Hz) at 178.0 and 177.8 ppm, consistent with other rhodium imidazole-NHCs[14,66,67]. The COD olefinic carbons also resonate as doublets at 92.4, 88.6, 87.5, and 85.4 ppm with coupling constants that range between 5 and 9 Hz.…”

“…Scheme 1 is a generic synthetic methodology for the preparation of C 2 -symmetric DEAM diazolium triflate salts [17,18,65,66]. The synthesis of the diazolium salts (S,S)-trans-1,1 0 -(9,10-dihydro-9,10-ethanoanthracene-11,12-diyldimethanediyl)bis(3-(2-methylphenyl-1-benzyl)-1H-benzimidazol-3-ium)bis(triflouromethansulfonate) [DEAM-o-MBBI][OTf] 2 (3) and (S,S,R,R)-trans-1,1 0 -(9,10-dihydro-9,10-ethanoanthracene-11,12-diyldimethanediyl)bis(3-(R-1-phenylethane)-1H-imidazol-3-ium) [DEAM-PEI][OTf] 2 (4) involves treating two equivalents of 1-benzyl(2-methylphenyl)-benzimidazole (1) or R-1-(1-phenylethyl)-1H-imidazole (2) [75] with an equivalent of (S,S)-trans-9,10-dihydro-9,10-ethanoanthracene-11,12-diyldimethanediyl bis(trifluoromethanesulfonate) [76] in refluxing DME.…”

“…Chart 1 depicts complexes employed in the catalytic studies (vide infra) that were prepared according to known literature [18], 10-Me [67], 11 [67,82], and 13 [66]), as well as four new species 8-o-MeBn, 9-RCHMePh, 10-i Pr, and 12. Complexes 8-o-MeBn and 9-R-CHMePh are synthesized in a one-pot method via combination of a metal precursor and in situ generation of the diNHC.…”

Synthesis of BINAM‐Based Chiral Di‐1,2,3‐triazolylidene Complexes and Application of the Di‐NHC RhI Catalyst in Enantioselective Hydrosilylation

“…[9][10][11][12][13][14][15][16][17][18] An example of such a "hybrid" system is Burgess and co-workers' oxazoline-functionalized NHC iridium hydrogenation catalyst, [19] which hydrogenates unfunctionalized olefins under 1 bar of H 2 with excellent enantioselectivities. [9][10][11][12][13][14][15][16][17][18] An example of such a "hybrid" system is Burgess and co-workers' oxazoline-functionalized NHC iridium hydrogenation catalyst, [19] which hydrogenates unfunctionalized olefins under 1 bar of H 2 with excellent enantioselectivities.…”

Human cancerous and healthy cell cytotoxicity studies of a chiral μ-dicarbene–digold(i) metallamacrocycle

“…33 Furthermore, the bis-NHC-Au I complexes were more active than the corresponding mono-NHC-Au I complexes. 28 This last discovery prompted us to apply our unique chiral diNHC ligand trans-9,10-D̲ ihydro-9,10-E̲ thanoA̲ nthracene-11,12-diylM̲ ethanediyl [34][35][36][37][38][39][40] (DEAM) to create new Au I complexes for application as anti-cancer agents. Another motivating factor was that no chiral NHC-Au I complexes had been tested; therefore, we sought to determine if cell-selectivity could be improved by employing chiral chrysotherapy.…”