Palladium(0)‐Catalyzed Hydroalkoxylation of Hexafluoropropene: Synthesis of Hydrofluoroethers under Neutral Conditions

Abstract

No vinyl ether by‐products are formed in the palladium(0)‐complex catalyzed hydroalkoxylation of hexafluoropropene (see scheme). Saturated hydrofluoroethers are selectively synthesized with alcohols or phenols under neutral conditions in the presence of [Pd(PPh3)4]/dppb. dppb=1,4‐bis(diphenylphosphanyl)butane.

Fluoride-catalyzed hydroalkoxylation of hexafluoropropene with 2,2,2-trifluoroethanol

“…The abstraction of HF from B will generate the anionic species, C. The subsequent elimination of F À from C would produce olefinic compounds. Alternatively, CF 3 CHFCF 2 OCH 2 CF 3 can be produced through a carbanionic mechanism involving the formation of (CF 3 ) 2 CF À M + , as described in the previous papers by Sekiya et al [15,18].…”

“…Besides the interaction with TFE, MF is also known to interact with HFP to form metal alkoxide and CF 3 active species for the hydroalkoxylation [15,18].…”

“…However, the alkylation method suffered from the relatively high cost of raw material and the difficulty in handling the toxic acyl fluorides. Recently, Matsukawa et al [15] reported that the hydroalkoxylation of fluoroolefins in the presence of a Pd 0 complex, [Pd(PPh 3 ) 4 ] was highly active for producing HFEs in high yield and selectivity. This is a great finding because the formation of commonly observed olefinic side products can be completely suppressed, but the use of an expensive Pd complex seems to be a major obstacle in the commercial application of this process [14].…”

Pd(0)/C catalyzed efficient Wacker oxidation of functionalized terminal olefins

“…[8][9][10]12 However, in case of all of the Wacker oxidations 14,15 carried out so far, Pd was used in the form of Pd(II) ion. Palladium has never been used in the form of Pd(0) for any Wacker oxidation as there are no reports in the literature 16,17 to this effect.…”

Nucleophilic and electrophilic substitutions of difluoropropargyl bromides

“…Prior to our disclosure, the synthesis of hydrofluoroethers could only be achieved under strongly basic conditions -that led to vinyl ether by-products -or through the very recently reported [34] Pd(0)-catalyzed hydroalkoxylation of hexafluoropropene. In addition to the alkyne functionality present in 3, the TIPS group is also a useful synthetic handle.…”