CH Bond Activation during and after the Reactions of a Metallacyclic Amide with Silanes: Formation of a μ-Alkylidene Hydride Complex, Its H-D Exchange, and β-H Abstraction by a Hydride Ligand
Metallacyclic complex [(Me2N)3Ta(η2‐CH2SiMe2NSiMe3)] (3) undergoes CH activation in its reaction with H3SiPh to afford a Ta/μ‐alkylidene/hydride complex, [(Me2N)2{(Me3Si)2N}Ta(μ‐H)2(μ‐C‐η2‐CHSiMe2NSiMe3)Ta(NMe2)2] (4). Deuterium‐labeling studies with [D3]SiPh show H–D exchange between the TaDTa u...
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Published in | Chemistry : a European journal Vol. 20; no. 20; pp. 6033 - 6039 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Weinheim
WILEY-VCH Verlag
12.05.2014
WILEY‐VCH Verlag |
Subjects | |
Online Access | Get full text |
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Summary: | Metallacyclic complex [(Me2N)3Ta(η2‐CH2SiMe2NSiMe3)] (3) undergoes CH activation in its reaction with H3SiPh to afford a Ta/μ‐alkylidene/hydride complex, [(Me2N)2{(Me3Si)2N}Ta(μ‐H)2(μ‐C‐η2‐CHSiMe2NSiMe3)Ta(NMe2)2] (4). Deuterium‐labeling studies with [D3]SiPh show H–D exchange between the TaDTa unit and all methyl groups in [(Me2N)2{(Me3Si)2N}Ta(μ‐D)2(μ‐C‐η2‐CHSiMe2NSiMe3)Ta(NMe2)2] ([D2]‐4) to give the partially deuterated complex [Dn]‐4. In addition, 4 undergoes β‐H ion between a hydride and an NMe2 ligand and forms a new complex [(Me2N){(Me3Si)2N}Ta(μ‐H)(μ‐N‐η2‐C,N‐CH2NMe)(μ‐C‐η2‐C,N‐CHSiMe2NSiMe3)Ta(NMe2)2] (5) with a cyclometalated, η2‐imine ligand. These results indicate that there are two simultaneous processes in [Dn]‐4: 1) H–D exchange through σ‐bond metathesis, and 2) HD elimination through β‐H ion (to give [Dn]‐5). Both 4 and 5 have been characterized by single‐crystal X‐ray diffraction studies.
A tantalum metallacyclic complex undergoes intramolecular CH activation upon reaction with H3SiPh to give a Ta/μ‐alkylidene/hydride complex, which then undergoes β‐H ion to form a complex with a bridging tantalaaziridine ligand (see scheme). |
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Bibliography: | ArticleID:CHEM201303166 Science Foundation of State Key Laboratory of Structural Chemistry - No. 20100009 ark:/67375/WNG-6QRV5XMZ-P US National Science Foundation - No. CHE-1012173 National Natural Science Foundation of China - No. 20861007; No. 21162015 istex:0A57B51F9E6639CB56F1EAB7CC2A02954A2CC847 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0947-6539 1521-3765 |
DOI: | 10.1002/chem.201303166 |