Transition metal-free stereospecific access to (E)-(1-fluoro-2-arylvinyl)phosphine borane complexes

Kevin Rousée (1) , Xavier Pannecoucke (1) , A.-C. Gaumont (2) , J.-F. Lohier (2) , F. Morlet-Savary (3) , J. Lalevée (3) , J.-P. Bouillon (1) , Samuel Couve-Bonnaire (1) , S. Lakhdar (2)

1 COBRA - Chimie Organique et Bioorganique : Réactivité et Analyse
2 LCMT - Laboratoire de chimie moléculaire et thioorganique
3 IS2M - Institut de Science des Matériaux de Mulhouse

This work describes the first transition metal-free stereospecific synthesis of (E)-(1-fluoro-2-arylvinyl)phosphine boranes through the addition of diarylphosphine-boranes to gem-bromofluoroalkenes in the presence of a base at room temperature. The reaction proceeds well under very mild conditions and tolerates a variety of functionalities. Scope and limitations of the reaction are discussed. Mechanistic investigations have been undertaken and revealed that the reaction takes place through an SRN1 mechanism. The formation of the fluorinated vinyl radical has been evidenced by electron paramagnetic resonance (EPR) experiment.

Domains: Chemical Sciences

Kevin Rousée, Xavier Pannecoucke, A.-C. Gaumont, J.-F. Lohier, F. Morlet-Savary, et al.. Transition metal-free stereospecific access to (E)-(1-fluoro-2-arylvinyl)phosphine borane complexes. Chemical Communications, 2017, 53 (12), pp.2048-2051. ⟨10.1039/C6CC09673E⟩. ⟨hal-01844270⟩