Reactivity of Rh(I) Complexes Toward Fluorinated Ethers: Activation of Inhalation Anesthetics

The reactivity of [Rh(H)(PEt 3 ) 3 ] ( 1 ) toward α‐fluorinated ethers that are commonly used as inhalational anesthetics was studied. Unprecedented reactivity pathways include hydrodehalogenation of sp 3 C─F and C─Cl bonds under mild conditions. The reaction of 1 with sevoflurane (CF 3 ) 2 CHOCH 2 F provides an efficient route to obtain [Rh(F)(PEt 3 ) 3 ] ( 2 ) by C( sp 3 )─F bond activation. Furthermore, the phosphine ligand takes part in this reaction, and an F/Et exchange at [Rh(H)(F) 2 (PEt 3 ) 3 ] results in the formation of the fluorophosphine complex trans ‐[Rh(F)(Et 2 PF)(PEt 3 ) 2 ] ( 5 ) upon the release of ethane. On the other hand, an oxidative addition of enflurane CClFHCF 2 OCF 2 H at 1 yielded [Rh(H)(Cl)(CFHCF 2 OCF 2 H)(PEt 3 ) 3 ] ( 8 ), which is followed by a reductive elimination step to yield [Rh(Cl)(PEt 3 ) 3 ] ( 7 ) and the hydrofluoroether CFH 2 CF 2 OCF 2 H. When an isomer of enflurane, isoflurane CF 3 CClHOCF 2 H, was treated with 1 , complex 7 and CF 3 CH 2 OCF 2 H are generated by C( sp 3 )─Cl bond activation. Additionally, an in situ nucleophilic attack of triethylphosphine at the hydrofluoroether CF 3 CH 2 OCF 2 H gave a unique fluorinated phosphonium salt [CF 3 CH 2 PEt 3 ] 2 [SiF 6 ] ( 9 ). Catalytic hydrodechlorination of isoflurane at a mild condition was achieved in the presence of silane HSiPh 3 using 1 as a catalyst.