C−H and C−F Bond Activation Reactions of Fluorinated Propenes at Rhodium: Distinctive Reactivity of the Refrigerant HFO‐1234yf

Abstract

The reaction of [Rh(H)(PEt 3 ) 3 ]( 1)w ith the refrigerant HFO-1234yf (2,3,3,3-tetrafluoropropene) affords an efficient route to obtain [Rh(F)(PEt 3 ) 3 ]( 3)b yC À Fb ond activation. Catalytic hydrodefluorinations were achieved in the presence of the silane HSiPh 3 .Inthe presence of afluorosilane, 3 provides aC ÀHb ond activation followed by a1 ,2-fluorine shift to produce [Rh{(E)-C(CF 3 )=CHF}(PEt 3 ) 3 ]( 4). Similar rearrangements of HFO-1234yf were observed at [Rh(E)-(PEt 3 ) 3 ][E= Bpin (6), C 7 D 7 (8), Me (9)].The ability to favor C À Hb ond activation using 3 and fluorosilane is also demonstrated with 3,3,3-trifluoropropene.S tudies are supported by DFT calculations.

Activation of tetrafluoropropenes by rhodium(i) germyl and silyl complexes

“…Note that complex 3 might be formed from 2 by C-H activation which is mediated by a germane, as previously observed for boranes and silanes. 4 The latter act as Lewis-acids and aer uoride abstraction, the C-H activation step at the coordinated olen is induced by the uoroborate or uorosilicate, respectively, to yield 3 and HF.…”

Palladium-catalysed C–F alumination of fluorobenzenes: mechanistic diversity and origin of selectivity

“…51 Similarly, Braun and coworkers very recently described the reaction of 2,3,3,3-tetrauoropropene with a Rh(I) complex that, in the presence of a uorosilane, proceeds by an initial C-H activation step followed by a 1,2-uorine atom shi. 52 While mechanistic data for these stepwise process operating for uoroarenes is less well described, Johnson and coworkers have proposed that reversible C-H activation occurs en route to nonreversible C-F activation during reactions with in situ generated [Ni(PEt 3 ) 2 ]. 53,54 Origin of selectivity For pathway 2, calculations clearly predict the C-F functionalisation pathway to be kinetically favoured and lead to the thermodynamic product.…”

Saturated N‐Heterocyclic Carbene Based Thiele's Hydrocarbon with a Tetrafluorophenylene Linker

“…Scheme1.Stepwise access to 3.C 6 F 6 was used in 1:2r atio with SIPr to perform the reaction at room temperature. Alarger amount of C 6 F 6 acts as a "fluorides huttle"; [9] Ar = 2,6-iPr 2 -C 6 H 3 . Figure 1.…”