Preparation of Trifluorostyrenes via Palladium-Catalyzed Coupling of Arylboronic Acids with Chloro- and Bromotrifluoroethylene

Abstract

A highly efficient and cost-effective method for the preparation of α,β,β-trifluorostyrene (TFS) and its derivatives is described. The method required only 0.2 mol % of Pd(dba)(2) and 0.4 mol % of P(t)Bu(3) and occurred to full conversion within 2.0 h. With this method, a wide range of arylboronic acids were efficiently incorporated to generate α,β,β-trifluorostyrene derivatives.

Carbon–Fluorine Bond Activation of Tetrafluoroethylene on Palladium(0) and Nickel(0): Heat or Lewis Acidic Additive Promoted Oxidative Addition

“…We found the CC bond distance of the coordinated trifluorovinyl group (1.297(8) Å for 16) to be equal within the margin of error to those observed in Hg(CFCF 2 ) 2 , (η 5 -C 5 Me 4 Et) 2 Ti(OH)(CFCF 2 ), (PPh 3 )Au(CFCF 2 ), [Ir 2 (η 1 -CFCF 2 )(CH 3 )(CO) 2 (μ-Cl)(dppm) 2 ](CF 3 SO 3 ), and Ph 3 Ge-(CFCF 2 ) (1.312( 6), 1.331(4), 1.297( 14), 1.298(9), and 1.230(8) Å, respectively) 29 as well as that in trans-(PPh 3 ) 2 Pd-(Cl)(CFCF 2 ) (1.270(4) Å). 25 The NMR spectra of 16 revealed that its molecular structure in solution is consistent with that observed in the solid state, in A similar procedure could be applied to the nickel analogue 4a, giving trans-(PCy 3 ) 2 Ni(BF 4 )(CFCF 2 ) (17), which was characterized on the basis of the observation of a similar fluxional behavior of the tetrafluoroborate anion in variabletemperature 19 F NMR spectra (Scheme 9).…”

“…It should be mentioned that a related (trifluorovinyl)palladium chloride complex, trans-(PPh 3 ) 2 Pd-(Cl)(CFCF 2 ), has recently been isolated and structurally defined by Lu, Shen, and co-workers. 25 Molecular Structures of Trifluorovinyl Metal Halides. The occurrence of the C−F bond cleavage of TFE was unambiguously confirmed by X-ray crystallography of 7 and 9, the results of which were previously reported in our recent communication (Figure 5).…”

Palladium-Catalyzed Cross-Coupling Reactions of Perfluoro Organic Compounds

“…In fact, the Pd(0)-catalyzed coupling reaction of chlorotrifluoroethylene with 8a in the absence of a base gave no coupling products, probably due to the generation of the unreactive trifluorovinylpalladium chloride intermediate. As mentioned above, the Pd-catalyzed coupling reaction of chlorotrifluoroethylene with arylboronic acids in the presence of a base has been reported [36,37]. Scheme 6.…”

“…A synthetic route involving a more stable trifluorovinyl borate has recently been developed to replace the zinc or tin reagents [34,35]. Alternative routes to synthesize (α,β,β-trifluoro)styrenes via the cross-coupling of chlorotrifluoroethylene with arylboronic acids have recently been reported [36,37]. Against such a background, we started developing a novel strategy for their preparation from 1, because 1 is an economical bulk organofluorine feedstock for the production of poly(tetrafluoroethylene) and co-polymers with other alkenes [38][39][40].…”

Stereospecific synthesis of (E)- and (Z)-1-chloro-1,2-difluorostyrenes

“…(6)). Subsequently, Long Lu et al [10] prepared trifluorostyrenes via Pd-catalyzed coupling of arylboronic acids with chloro-and bromotrifluoroethylene (Eq. (7)):…”