Regio- and Stereoselective Functionalization ofcyclo-C8 Compounds by Iterative Nucleophilic and Electrophilic Addition to Coordinated Cyclooctatetraene

[(η6‐Cyclooctatetraene){η5‐(+)‐neomenthylcyclopentadienyl}ruthenium(II)] Hexafluorophosphate: Synthesis and Characterization of a Chiral Mixed Sandwich Complex

“…Complex 3 displays 1 H and 13 C NMR signals due to the (+)‐neomenthyl substituent ( 1 H: δ = 0.7−2.9 ppm; 13 C: δ = 20−50 ppm), and the Cp and COT ligands ( 1 H: δ = 5.0−6.3 ppm; 13 C: δ = 82−138 ppm). The 1 H and 13 C chemical shifts of the metal‐bound hydrocarbon units clearly testify to the cationic nature of 3 ,1b and the number of signals confirms the formation of a single stereoisomer. Due to the chiral (+)‐neomenthyl substituent all of the Cp protons are inequivalent and give rise to four multiplets in the range δ = 5.3−5.6 ppm, consistent with the chemical shifts observed in other monocationic CpRu sandwich complexes 1,8…”

“…Most notably, the C7−C8 bond lengths in the disordered model were not chemically sensible; a nondisordered model was thus used and refined anisotropically. The Ru−C(COT) bond lengths of 214.1−222.6 pm are in the typical range of cationic (η 6 ‐ cyclo ‐C 8 )Ru complexes 1b. The distances between the Ru center and the carbon atoms of the Cp ligand of 218.1(2)−222.98(19) pm correspond to Ru−C(Cp) bond lengths of other cationic CpRu complexes7 except for the bond to C9 [226.14(16) pm], the atom which bears the (+)‐neomenthyl substituent.…”

Metal-Mediated Transformations of Cyclooctatetraene to Novel Methylene-Bridged, Bicyclic Compounds

“…The X-ray structure determinations of 2a (Nu 1 = C(CO 2 Et) 2 CH 2 CHCH 2 ) (Figure ) and 2b (Nu 1 = C(CO 2 Et) 2 (CH 2 ) 2 CHCH 2 ) (Figure ) reveal a 1,2,3,4,5-η coordination mode of the cyclooctatrienyl ligand. This coordination can easily be proven by 1 H- 1 H and 1 H- 13 C correlation spectroscopy for other products of 2 and differs from the 1,2-η:5,6,7-η coordination mode, which is found for corresponding Ru complexes 3 XSHELL style representation of the molecular structure of 2b as determined by single-crystal X-ray crystallography.…”

Pentamethylcyclopentadienyl(η6‐cyclooctatrienyl)ruthenium Tetrachlorozincate, [RuCp*(η6‐C8H10)]2ZnCl4

“…While many ruthenium complexes containing the pentamethylcyclopentadienyl ligand have been described, including many [RuCp*(η 6 ‐arene)] + cations,1 structurally characterised examples containing the Ru(η 5 ‐C 5 ‐ring)(η 6 ‐C 8 ‐ring) moiety appear to be limited to the [Ru(η 5 ‐neomenthyl‐C 5 H 4 )(η 6 ‐C 8 H 8 )] + cation ( 1 ) 2. Further examples of complexes of this type have been obtained by the addition of nucleophiles to [RuCp(η 6 ‐C 8 H 8 )] + , followed by protonation, although the X‐ray structural study of [RuCp(C 8 H 8 Ph)]BF 4 showed that the 1,2‐η 2 :4,5,6,7‐η 4 ‐C 8 H 9 Ph haptomer had formed 3…”