Recent advances in the chemistry of heterometallacycles of group 4 metallocenes

Reactions of Group 4 Metallocenes with N,N′‐Diphenylformamidine – Hydrogen Generation versus Oxidative Addition

“…Several such reactions were observed producing different all-C [2] and hetero-metallacycles. [3] Recently, we reported the synthesis of zirconocene hydrido amidato complexes as a result of formal oxidative addition of an amidic N-H bond at reduced central zirconium atoms, offering a facile synthetic pathway to an alternative and tunable Schwartz's reagent. [4] Also the reaction behavior of various differently substituted titanocene precursor complexes CpЈ 2 of titanocene(III) amidato complexes (Scheme 1) upon oxidation of the central titanium atom.…”

Reactions of [Cp2Ti(η2‐Me3SiC2SiMe3)] with 1,4‐Bis(diphenylphosphanyl)but‐2‐yne: Coupling and Isomerization versus Phosphorylation

“…It is worth mentioning that such butatrienes and but-2-en-3-ynes are coordinated by group 4 metallocenes to give strained metallacycles such as 1-metallacyclopenta-3-ynes and metallacycloallenes. [15] Like compound 2 used herein, the very similar 1,4-disubstituted but-2-yne substrate 1,4-dichlorobut-2-yne also forms 1-metallacyclopentynes. [16] Also, ClMe 2 SiCϵCSiMe 2 Cl yields 1-metalla-2,5-disilacyclopentynes after Cl abstraction.…”

Nitril‐Nitril‐C‐C‐Kupplungen an Gruppe‐4‐Metallocenen zu 1‐Metalla‐2,5‐diazacyclopenta‐2,4‐dienen und deren Reaktionen

“…Bei einem Überschuss des Alkins kçnnen durch die Kupplung von zwei Substraten 1-Metallacyclopenta-2,4-diene gebildet werden. [2] Diese Ergebnisse veranlassten uns, die Bildung der Heterometallacyclen, [3] der entsprechenden 1-Metalla-2,5-diazacyclopenta-2,4-diene, durch die Kupplung von zwei Nitrilen zu untersuchen. Nitrile sind für die Entwicklung neuer Synthesestrategien von ganz besonderem Interesse, da sie sehr gebräuchlich und vielseitig sind.…”