Einfacher Zugang zu Li- oder Zn-metallierten η5-Cyclopentadienyleisen-Olefin-Komplexen

Towards Homoleptic Naphthalenemetalates of the Later Transition Metals: Isolation and Characterization of Naphthalenecobaltates(1−)

“…1 H and 13 C NMR spectra of 1 in solution are unexceptional and entirely consistent with its formulation, and showed resonances characteristic of η 4 ‐naphthalene7, 8 and η 4 ‐1,5‐cyclooctadiene3, 12 groups bound in a 1:1 ratio to an electron‐rich metal center. A single‐crystal X‐ray study on 1 , as the [K([18]crown‐6)] salt, revealed an undistorted cation that was well‐separated from the cobalt center of the anion and had no significant effect on its structure 13.…”

Maternal serum placental growth factor at 11 + 0 to 13 + 6 weeks of gestation in the prediction of pre‐eclampsia

“…Analogous reactions of 1 with excess 1,5‐cyclooctadiene (cod) gave no evidence for the formation of unknown paramagnetic [Fe(η 4 ‐cod) 2 ] − or reported [Fe(η 4 ‐cod) 2 ] 2− ,26 but instead afforded the first example of a mixed‐ligand or heteroleptic Fe −I complex, [Fe(η 4 ‐C 14 H 10 )(η 4 ‐cod)] − ( 5 ). This species was isolated in good yield as teal or dichroic red‐violet microcrystals of the [K([18]crown‐6)] + ( 5 a ) or [K([2.2.2]cryptand)] + ( 5 b ) salts, respectively.…”

Secondary Alkyl Halides in Transition‐Metal‐Catalyzed Cross‐Coupling Reactions

“…Although the mechanisms of iron‐catalyzed cross‐coupling reactions have not been elucidated (see Section 3.3), it has been postulated that highly reduced iron–magnesium clusters containing an iron(−II) center, such as [Fe(MgX) 2 ] n , may play an important role in the catalytic cycle. Martin and Fürstner probed this theory by testing the known, well‐defined iron(−II) complex [Li(tmeda)] 2 [Fe(C 2 H 4 ) 4 ] ( 8 ), which was first described by Jonas and co‐workers,30a, b as a catalyst for cross‐coupling reactions 30c. Indeed, 8 is a very active catalyst for the coupling of aryl Grignard reagents with alkyl electrophiles, including secondary alkyl bromides (Scheme ).…”