Research & Teaching Faculty

Default Header Image

Synthesis, Structure, and Insertion Reactivity of Zirconium and Hafnium Amidate Benzyl Complexes.

TitleSynthesis, Structure, and Insertion Reactivity of Zirconium and Hafnium Amidate Benzyl Complexes.
Publication TypeJournal Article
Year of Publication2010
AuthorsThomson, RK, Schafer, LL
JournalOrganometallics
Volume29
Pagination3546 - 3555
Date Published2010///
ISBN Number0276-7333
Keywordsbenzyl zirconium hafnium amidate complex prepn crystal mol structure, iminoacyl zirconium amidate complex prepn crystal mol structure, isocyanide insertion benzyl zirconium amidate complex, vinylamido enediamido zirconium complex prepn
Abstract

A series of amidate-ligated dibenzyl zirconium and hafnium complexes are accessed through protonolysis reactions of the amide proligands 2,6-dimethylphenylpivaloylamide, [DMP(NO)tBu]H (3), and 1,3-bis(1-adamantylamide)-2,2-dimethylpropane, Ad[O2N2]H2 (5), with Zr(CH2Ph)4 or Hf(CH2Ph)4. The resulting dibenzyl complexes [DMP(NO)tBu]2Zr(CH2Ph)2 (4), Ad[O2N2]Zr(CH2Ph)2(THF) (6), and Ad[O2N2]Hf(CH2Ph)2(THF) (7) are structurally characterized. Insertion reactions of 4 with isocyanides are investigated, resulting in the formation of an η2-iminoacyl species, [DMP(NO)tBu]2Zr(η2-2,6-Me2C6H3N:CCH2Ph)2 (8), which undergoes thermal C:C coupling to form an enediamido complex, [DMP(NO)tBu]2Zr(η4-ArNC(CH2Ph):C(CH2Ph)NAr) (Ar = 2,6-Me2C6H3) (9). Analogous insertion of tBuN=C into the Zr-C bonds of 4 results in the formation of a vinylamido complex, [DMP(NO)tBu]2Zr(N(tBu)CH:CHPh)2 (10), through a presumed 1,2-hydrogen migration mechanism from an iminoacyl intermediate similar to 8. Complexes 8 and 9 are also structurally characterized. [on SciFinder(R)]