C−H and C−F Bond Activation Reactions of Fluorinated Propenes at Rhodium: Distinctive Reactivity of the Refrigerant HFO‐1234yf. Issue 31 (1st July 2019)

• Record Type: Journal Article
• Authors: Talavera, Maria; von Hahmann, Cortney N.; Müller, Robert; Ahrens, Mike; Kaupp, Martin; Braun, Thomas
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 31(2019)
• Page Start: 10688
• Page End: 10692
• Publication Date: 2019-07-01
• Subjects: C−H activation -- fluorine -- olefins -- rhodium -- silanes; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201902872
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The reaction of [Rh(H)(PEt3 )3 ] (1 ) with the refrigerant HFO‐1234yf (2, 3, 3, 3‐tetrafluoropropene) affords an efficient route to obtain [Rh(F)(PEt3 )3 ] (3 ) by C−F bond activation. Catalytic hydrodefluorinations were achieved in the presence of the silane HSiPh3 . In the presence of a fluorosilane, 3 provides a C−H bond activation followed by a 1, 2‐fluorine shift to produce [Rh{( E )‐C(CF3 )=CHF}(PEt3 )3 ] (4 ). Similar rearrangements of HFO‐1234yf were observed at [Rh(E)(PEt3 )3 ] [E=Bpin (6 ), C7 D7 (8 ), Me (9 )]. The ability to favor C−H bond activation using 3 and fluorosilane is also demonstrated with 3, 3, 3‐trifluoropropene. Studies are supported by DFT calculations. Abstract : Cool down : Using the refrigerant HFO‐1234yf together with [RhH(PEt3 )3 ], a C−F bond activation occurs to produce a rhodium fluorido complex. This reaction is followed by a C−H bond activation mediated by the fluorosilane and a subsequent 1, 2‐fluorine shift.