36 research outputs found
ChemInform Abstract: Asymmetric Hydrogenation of Phenylthio Ketones with Chiral Ru(II) Catalysts.
Evaluating the performance of the dynamic bandwidth reservation method using link utilization information in automatic transfer mode local area networks
Reactivity and diastereoselectivity of Grignard reagents toward the hydrazone functionality in toluene solvent
Réactivité des complexes (η<sup>5</sup>-cyclohexadiényl)Mn(CO)<sub>3</sub> substitués par des groupes électroattracteurs vis-à -vis d'hydrures
Enantiopure Cyclometalated Rh(III) and Ir(III) Complexes Displaying Rigid Configuration at Metal Center: Design, Structures, Chiroptical Properties and Role of the Iodide Ligand
International audienceEnantiopure N-heterocyclic carbene half-sandwich metal complexes of the general formula [Cp*M(C^C:)I] (M = Rh, Ir; C^C: = NI-NHC; NI-H = Naphthalimide; NHC = N-heterocyclic carbene) are reported. The rhodium compound was obtained as a single isomer displaying six membered metallacycle and was resolved on chiral column chromatography to the corresponding enantiomers (S)-[Cp*Rh(C^C:)I] (S)-2 and (R)-[Cp*Rh(C^C:)I] (R)-2. The iridium congener, however, furnishes a pair of regioisomers, which were resolved into (S)-[Cp*Ir(C^C:)I] (S)-3 and (R)-[Cp*Ir(C^C:)I] (R)-3 and (S)-[Cp*Ir(C^C:)I] (S)-4 and (R)-[Cp*Ir(C^C:)I] (R)-4. These regioisomers differ from each other, only by the size of the metallacycle; five-membered for 3 and six-membered for 4. The molecular structures of (S)-2 and (S)-4 are reported. Moreover, the chiroptical properties of these compounds are presented and discussed. These compounds display exceptional stable configurations at the metal center in solution with enantiomerization barrier ÎGâ up to 124 kJ/mol. This is because the nature of the naphthalimide-NHC clamp ligand and the iodide ligand contribute to their configurationâs robustness. In contrast to related complexes reported in the literature, which are often labile in solution