Ethyltetramethylcyclopentadienyl complexes of cobalt, rhodium, iridium and ruthenium

Abstract

The syntheses of the ethyltetramethylcyclopentadienyl complexes Ru(r/s-cs Me4 Et)(CO)2 el, Co(//s -C s Me4 Et)(CO)2, and [M(rlS-c5 Mea Et)CI2 ]2 (M = Rh or It) are described; the ruthenium complex reacts with triphenylarsine to give Ru('r/S-cs Me 4 Et)(AsPh3 )(co)el. I H and 13C n.m.r, spectra, i.r. spectra and the physical properties of the compounds are discussed and contrasted with the known Cs Hs and CsMcs analogues.

Replacement of One CO Unit in Dicarbonyl(η5-cyclopentadienyl)cobalt Derivatives by Bis(tert-butylsulfonyl)acetylene

“…Ϫ Materials used for column chromatography: Silica gel 60 (Macherey-Nagel), alumina (Merck). [3] , 2 [14] , 3 [15] [ 16] , 4 [17] , and 5 [18] [19] were prepared according to literature methods. 5 -pentaallylcyclopentadienyl)cobalt (6).…”

“…In this paper we report experiments with 1 [3] and the substituted congeners dicarbonyl(η 5 -methylcyclopentadienyl)-(2) [14] , dicarbonyl(η 5 -trimethylsilylcyclopentadienyl)- (3) [15] [16] , dicarbonyl(η 5 -methoxycarbonylcyclopentadienyl)-(4) [17] , dicarbonyl-(η 5 Ϫ1-ethyl-2,3,4,5-tetramethylcyclopentadienyl)-(5) [18] [19] , and dicarbonyl(η 5 -pentaallylcyclopentadienyl)cobalt (6) [20] .…”

Effect of a Substituent in Cyclopentadienyl Ligand on Iridium-Catalyzed Acceptorless Dehydrogenation of Alcohols and 2-Methyl-1,2,3,4-tetrahydroquinoline

“…On the basis of our previous studies, in which Cp* iridium complexes exhibited excellent catalytic activity [36][37][38][39][40][41][42][43][44][45][46][47], we attempted to modify one methyl group in the Cp* ligand to hydrogen, ethyl, isopropyl, and t-butyl groups in order to improve the catalytic properties (Scheme 2). A series of cyclopentadienyl-ligated iridium dichloride dimers 1a-1e were synthesized by the reaction of iridium trichloride with parent cyclopentadiene derivatives [62][63][64]. The structure of novel complex 1e was successfully identified by X-ray crystallographic analysis.…”

“…The resulting solid was filtered with glass filter and washed with H 2 O (10 mL). The title compound was obtained as a green yellow solid (121.1 mg, 0.211 mmol, 63…”

Synthesis, Properties and Formation of (RCp)Co‐ and (RCp)Rh‐Stabilized[4.8]3Cyclacene Derivatives

“…All reactions were carried out in dried glassware under argon atmosphere using dried and oxygen-free solvents. The reagents 5,6,11,12-tetradehydro-dibenzeno-A C H T U N G T R E N N U N G [a,e]cyclooctene (10), [14] [(h 5 -cyclopentadienyl)(dicarbonyl)cobalt] (11), [15] [(h 5 -methoxycarbonylcyclopentadienyl)(dicarbonyl)cobalt] (13), [15,30] [(h 5 -cyclopentadienyl)(diethenyl)rhodium] (18), [16,17,18] [(h 5 -methylcarbonyl- (14), [31] [(h 5 -trimethylsilylcyclopentadienyl)(dicarbonyl)cobalt](15), [32] [(h 5 -pentamethyl-cyclopentadienyl)-(dicarbonyl)cobalt](16), [33] [(h 5 -ethyltetramethylcyclopentadienyl)(dicarbonyl)cobalt] (17), [34] [(h 5 -methoxycarbonylcyclopentadienyl)(diethenyl)-A C H T U N G T R E N N U N G rhodium] (19), [35,36,37] [(h (20), [35,36,37] [(h 5 -chlorocyclopentadienyl)(diethenyl)rhodium]-A C H T U N G T R E N N U N G (21), [38] [(h 5 -pentamethylcyclopentadienyl)(diethenyl)rhodium] (22) [39] and several cyclacenes (12, 23, 25 and 26) [10] were prepared according to literature procedures.…”