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Thermal Isomerization of the Buchwald Seven-Membered Zirconacyclocumulene and Its Interaction with Acetylenes. Synthesis and Structures of Novel Seven-Membered Zirconacyclocumulene Complexesстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 23 января 2016 г.
- Авторы: Burlakov V.V., Bogdanov V.S., Arndt P., Baumann W., Spannenberg A., Лысенко К.А., Ananyev I.V., Rosenthal U., Shur V.B.
- Журнал: Organometallics
- Том: 34
- Год издания: 2015
- Издательство: American Chemical Society
- Местоположение издательства: United States
- Первая страница: 2471
- Последняя страница: 2480
- DOI: 10.1021/om501205s
- Аннотация: On prolonged heating of the Buchwald seven-membered zirconacyclocumulene Cp2Zr[η4-Me3SiC4(SiMe3)–C(C2SiMe3)═CSiMe3] (1) in toluene at 100 °C, the isomerization of 1 takes place with the formation of a seven-membered zirconacyclocumulene complex, Cp2Zr[η4-Me3SiC4(SiMe3)–C(SiMe3)═C(C2SiMe3)] (8), containing the Me3SiC≡C group in α-position and the SiMe3 group in β-position with respect to the Zr atom. A remarkable peculiarity of complex 8 is its ability to undergo a rapid degenerate rearrangement at room temperature in toluene solution, as a result of which only two rather than four singlets of the Me3Si groups are observed in the 1H NMR spectrum of 8 under such conditions. At temperatures below 200 K, the rate of this rearrangement decreases and, as a consequence, the 1H NMR spectrum of 8 acquires the normal view. If 1 is heated at 100 °C in the presence of acetylenes such as 1,4-bis(tert-butyl)butadiyne (tBuC≡C–C≡CtBu) and tolane, the corresponding seven-membered zirconacyclocumulenes, viz., Cp2Zr[η4-tBuC4(tBu)–C(C2SiMe3)═CSiMe3] (7) and Cp2Zr[η4-Me3SiC4(SiMe3)–C(Ph)═CPh] (14), are formed along with free Me3SiC≡C–C≡CSiMe3. The interaction of 1 with 1,4-diphenylbutadiyne (PhC≡C–C≡CPh) at 100 °C leads to the formation of a mixture of products, from which a zirconacyclopentadiene metallacycle, Cp2Zr[η2-PhC═C(C2Ph)–C(C2Ph)═CPh] (10), as well as seven-membered zirconacyclocumulenes Cp2Zr[η4-PhC4(Ph)–C(C2SiMe3)═CSiMe3] (11), Cp2Zr[η4-Me3SiC4(SiMe3)–C(C2Ph)═CPh] (12), and Cp2Zr[η4-PhC4(Ph)–C(C2Ph)═CPh] (13) were isolated. The structures of 8, 9, 10, 12, and 14 have been established by X-ray crystallography. The mechanism of the reactions found is discussed.
- Добавил в систему: Шилина Марина Ильинична