title: Functionalized cyclopentadienyl rhodium(III) bipyridine complexes: synthesis, characterization, and catalytic application in hydrogenation of ketones.
abstract: A series of highly functionalized cyclopentadienyl rhodium(III) complexes, [Cp'Rh(bpy)Br](ClO4) (Cp' = substituted cyclopentadienyl), was synthesized from various multi-substituted cyclopentadienes (Cp'H). [Rh(cod)Cl]2 and Cp'H were firstly converted to [Cp'Rh(cod)] complexes, which were then treated with Br2 to give the rhodium(III) dibromides [Cp'RhBr2]2. The novel complexes [Cp'Rh(bpy)Br](ClO4) were obtained readily by the reaction of 2,2'-bipyridine with [Cp'RhBr2]2. These rhodium complexes [Cp'Rh(bpy)Br](ClO4) were fully characterized and utilized in the hydrogenation of cyclohexanone and acetophenone with generally high yields, but they did not exhibit the same reactivity trends for the two substrate ketones. The different activity of these complexes for the different substrates may be due to the influence of the substituents on the Cp' rings.
authors.affiliation: National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5-2, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
authors.forename: Wan-Hui
authors.initials: WH
authors.lastname: Wang
authors.forename: Yuki
authors.initials: Y
authors.lastname: Suna
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Himeda
authors.forename: James T
authors.initials: JT
authors.lastname: Muckerman
authors.forename: Etsuko
authors.initials: E
authors.lastname: Fujita
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry*; D002384:Catalysis; D003517:Cyclopentanes / Q000737:chemistry*; D006865:Hydrogenation; D007659:Ketones / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*
chemical_list: D003517:Cyclopentanes; D007659:Ketones; D009942:Organometallic Compounds; D015082:2,2'-Dipyridyl; D012238:Rhodium