Application of Elemental Lanthanides in the Selective C-F Activation of Trifluoromethylated Benzofulvenes Providing Access to Various Difluoroalkenes - Université de Montpellier Accéder directement au contenu
Article Dans Une Revue Journal of visualized experiments : JoVE Année : 2018

Application of Elemental Lanthanides in the Selective C-F Activation of Trifluoromethylated Benzofulvenes Providing Access to Various Difluoroalkenes

Résumé

The selective activation of one carbon-fluorine bond in polyfluorinated aromatic molecules or in trifluoromethyl-containing substrates offers the possibility of accessing unique fluorine-containing molecules, which are difficult to obtain by other synthetic pathways. Among various metals, which can undergo C-F activation, lanthanides (Ln) are good candidates as they form strong Ln-F bonds. Lanthanide metals are strong reducing agents with a redox potential Ln3+/Ln of approximately -2.3 V, which is comparable to the value of the Mg2+/Mg redox couple. In addition, lanthanide metals display a promising functional group tolerance and their reactivity can vary along the lanthanide series, making them suitable reagents for fine-tuning reaction conditions in organic and organometallic transformations. However, due to their oxophilicity, lanthanides react readily with oxygen and water and therefore require special conditions for storage, handling, preparation, and activation. These factors have limited a more widespread use in organic synthesis. We herein present how dysprosium metal - and by analogy all lanthanide metals - can be freshly prepared under anhydrous conditions using glovebox and Schlenk techniques. The freshly filed metal, in combination with aluminum chloride, initiates the selective C-F activation in trifluoromethylated benzofulvenes. The resulting reaction intermediates react with nitroalkenes to obtain a new family of difluoroalkenes.

Domaines

Chimie

Dates et versions

hal-01887678 , version 1 (04-10-2018)

Identifiants

Citer

Tarun Kumar, Amira Ben Hassine, Agathe Martinez, Dominique Harakat, Sylviane Chevreux, et al.. Application of Elemental Lanthanides in the Selective C-F Activation of Trifluoromethylated Benzofulvenes Providing Access to Various Difluoroalkenes. Journal of visualized experiments : JoVE, 2018, 137, ⟨10.3791/57948⟩. ⟨hal-01887678⟩
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