A stable 16-electron rhodium(III) rhodacarborane derived from an intermediate containing an agostic hydrogen atom. Molecular structure of closo-3-(.eta.3-C8H13)-1,2-(CH3)2-3,1,2-RhC2B9H9

Mechanistic Studies on Rhodium-Catalyzed Enantioselective Silylation of Aryl C–H Bonds

“…The signals at the chemical shift of −3.12 ppm ( 5 ) and −3.24 ppm ( 5′ ) were assigned to the agostic protons. These chemical shifts are more downfield than those of terminal rhodium hydride complexes − and are similar to those of other metal complexes that contain norbornyl ligands with agostic interactions. − The 1 J C–H coupling constant of the agostic C–H bond of 5′ was ∼60 Hz at −80 °C, as determined by 2D J -resolved 13 C NMR spectroscopic analysis. This value is significantly lower than those of the analogous free C–H bonds and agrees with the previously reported values for C–H bonds engaged in agostic interactions .…”

Versatility of nido-Monophosphinocarboranes as Ligands. Tricoordination via PPh2 and BH in Rhodium(I) Complexes

“…They are active catalysts in the hydrogenation of terminal alkenes. Up to now, in every Rh(I) complex containing a C 2 B 9 nido cluster, this had been found coordinated to Rh(I) as a bidentate ligand. − Here, we report on the synthesis and crystallographic characterization of the first Rh(I) complex where the carborane ligand acts as a tricoordinating moiety. Moreover, this unique complex contains two B−H→Rh interactions and is the first exo-nido complex with cycloocta-1,5-diene as ancillary ligand.…”

“…Rhodacarboranes , containing phosphine or alkene ligands showed exceptional activity in the hydrogenation of terminal , and internal alkenes, , respectively. In earlier papers, we described the syntheses of rhodacarboranes based on nido- dithiocarborane and nido -diphosphinocarborane ligands.…”

Facile Carbon−Carbon Bond Cleavage in an (η3-Cyclooctenyl)cobalt Complex Exhibiting Agostic C···H···Co Bonding

“…The reaction of noncoordinating acids with d 8 [L 3 M(η 4 -cyclooctadiene)] n [ n = 0 or −1; Fe, Ru, − Os,16b Co, Rh, − Ir 17,20,21 ] complexes has been an extensively researched area of organometallic chemistry. Typically 22 the reaction affords metal diene−hydride complexes [M = Ru, − Os,16b Ir 17,20 ] and/or η 3 -cyclooctenyl complexes exhibiting three-center, two-electron C···H···M interactions [M = Fe, Ru, 14a,b Rh 18 ].…”