English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Ligand Exchange on and Allylic C−H Activation by Iron(0) Fragments: π‑Complexes, Allyliron Species, and Metallacycles

Casitas, A., Krause, H., Lutz, S., Goddard, R., Bill, E., & Fürstner, A. (2018). Ligand Exchange on and Allylic C−H Activation by Iron(0) Fragments: π‑Complexes, Allyliron Species, and Metallacycles. Organometallics, 37(5), 729-739. doi:10.1021/acs.organomet.7b00571.

Item is

Basic

show hide
Item Permalink: http://hdl.handle.net/21.11116/0000-0000-FBC7-5 Version Permalink: http://hdl.handle.net/21.11116/0000-0000-FBC8-4
Genre: Journal Article

Files

show Files
hide Files
:
[372]SI.pdf (Supplementary material), 2MB
Name:
[372]SI.pdf
Description:
Supporting Information
Visibility:
Public
MIME-Type / Checksum:
application/pdf / [MD5]
Technical Metadata:
Copyright Date:
-
Copyright Info:
-
License:
-

Locators

show

Creators

show
hide
 Creators:
Casitas, Alicia1, Author              
Krause, Helga1, Author              
Lutz, Sigrid2, Author              
Goddard, Richard3, Author              
Bill, Eckhard4, Author
Fürstner, Alois1, Author              
Affiliations:
1Research Department Fürstner, Max-Planck-Institut für Kohlenforschung, Max Planck Society, ou_1445584              
2Research Group Cornellà, Max-Planck-Institut für Kohlenforschung, Max Planck Society, ou_2466693              
3Service Department Lehmann (EMR), Max-Planck-Institut für Kohlenforschung, Max Planck Society, ou_1445625              
4Max-Planck-Institut für Chemische Energiekonversion, 45470 Mülheim/Ruhr, Germany, ou_persistent22              

Content

show
hide
Free keywords: -
 Abstract: The complexes [(dippp)Fe(C2H4)2] (2) and [CpFe(C2H4)2][Li·(tmeda)] (5) both contain a formally zerovalent iron center but exhibit markedly different catalytic properties. Whereas 5 is able to induce a broad range of cycloisomerization and cycloaddition reactions, 2 is so far basically limited to cyclotrimerizations of alkynes and nitriles. Investigations into the behaviors of both complex vis-à-vis unsaturated substrates provided insights into the likely origins of this distinct behavior. Thus, ordinary terminal or internal alkenes were found not to replace the ligated ethylene units in 2, whereas the stronger π-acceptor ligands 1,5-cyclooctadiene, 2- norbornene, and tolane afforded the corresponding π-complexes 8, 9, 10, and 13. A cyclopropene derivative engaged in oxidative cyclization with formation of the corresponding metallacycle 12. Allyl-9-BBN or alkenyl-9-BBN derivatives succumbed to allylic C−H activation with formation of the unorthodox allyliron complexes 25 and 27 featuring a bridging hydride ligand between the iron and the boron atoms. Along the same line, 1,3-dienes bind well to 2 but undergo spontaneous activation if allylic C−H bonds are present; the resulting hydride is transferred to a residual ethylene ligand, as manifest in the formation of the cyclopentadienyl ethyl complex 22. The same elementary steps surface in a remarkable reaction cascade comprising two consecutive C−H activation reactions and a stereoselective C−C bond formation, which ultimately provides the substituted cyclohexadienyl complexes 20 and 23. In contrast, the heterobimetallic complex 5 neither induces allylic C−H activation nor binds 1,3-butadiene under conditions where it proved catalytically active. The targeted butadiene complex 34 had to be made by an indirect route and is distinguished by a noteworthy "flyover" constitution. Therefore, we conclude that the known cycloaddition and cycloisomerization reactions catalyzed by 5 do not commence at a 1,3-diene motif but require an enyne entity as starter unit.

Details

show
hide
Language(s): eng - English
 Dates: 2017-07-272017-09-082018-03-12
 Publication Status: Published in print
 Pages: 11
 Publishing info: -
 Table of Contents: -
 Rev. Method: Peer
 Identifiers: DOI: 10.1021/acs.organomet.7b00571
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Organometallics
  Other : Organometallics
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: Washington, D.C. : American Chemical Society
Pages: - Volume / Issue: 37 (5) Sequence Number: - Start / End Page: 729 - 739 Identifier: ISSN: 0276-7333
CoNE: /journals/resource/954925505259