Milner, Lucy M., Hall, Lewis M., Pridmore, Natalie E. et al. (4 more authors) (2016) Access to novel fluorovinylidene ligands via exploitation of outer-sphere electrophilic fluorination:New insights into C-F bond formation and activation. Dalton Transactions. pp. 1717-1726. ISSN 1477-9226
Abstract
Metal vinylidene complexes are widely encountered, or postulated, as intermediates in a range of important metal-mediated transformations of alkynes. However, fluorovinylidene complexes have rarely been described and their reactivity is largely unexplored. By making use of the novel outer-sphere electrophilic fluorination (OSEF) strategy we have developed a rapid, robust and convenient method for the preparation of fluorovinylidene and trifluoromethylvinylidene ruthenium complexes from non-fluorinated alkynes. Spectroscopic investigations (NMR and UV/Vis), coupled with TD-DFT studies, show that fluorine incorporation results in significant changes to the electronic structure of the vinylidene ligand. The reactivity of fluorovinylidene complexes shows many similarities to non-fluorinated analogues, but also some interesting differences, including a propensity to undergo unexpected C-F bond cleavage reactions. Heating fluorovinylidene complex [Ru(η5-C5H5)(PPh3)2(CC{F}R)][BF4] led to C-H activation of a PPh3 ligand to form an orthometallated fluorovinylphosphonium ligand. Reaction with pyridine led to nucleophilic attack at the metal-bound carbon atom of the vinylidene to form a vinyl pyridinium species, which undergoes both C-H and C-F activation to give a novel pyridylidene complex. Addition of water, in the presence of chloride, leads to anti-Markovnikov hydration of a fluorovinylidene complex to form an α-fluoroaldehyde, which slowly rearranges to its acyl fluoride isomer. Therefore, fluorovinylidenes ligands may be viewed as synthetic equivalents of 1-fluoroalkynes providing access to reactivity not possible by other routes.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016, The Royal Society of Chemistry. |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Chemistry (York) The University of York |
Depositing User: | Pure (York) |
Date Deposited: | 23 Aug 2016 14:03 |
Last Modified: | 17 Mar 2025 00:06 |
Published Version: | https://doi.org/10.1039/c5dt04596g |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1039/c5dt04596g |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:104014 |