Fluorous benzotrifluoride

Maul JJ, Ostrowski PJ, Ublacker GA, Linclau B, Curran DP (1999) Benzotrifluoride and Deri-vates Useful Solvents for Organic Synthesis and Fluorous Synthesis. 206 79-105 McDonnell KA, see Imperiali B (1999) 202 1-38 McKelvey CA, see Hentze H-P (2003) 226 197-223... 

The fluorous Stille procedure has also been applied to a one-pot hydrostannylation of an acetylenic compound in the hybrid fluorous/organic solvent benzotrifluoride (BTF). Subsequent Stille coupling of the product in BTF/DM F, as shown in Eq. (11.32), was easily achieved in 8 min with 60 W single-mode microwave irradiation [43],... 

In an additional application of fluorous chemistry, radical-mediated cyclizations were performed in benzotrifluoride using microwave irradiation [70]. In the pre-... 

Benzotrifluoride dissolves both organic substrates/products and fluorous tin reagent... 

Tris[(2-perfluorohexyl)ethyl]tin hydride has three perfluorinated segments with ethylene spacers and it partitions primarily (> 98%) into the fluorous phase in a liquid-liquid extraction. This feature not only facilitates the purification of the product from the tin residue but also recovers toxic tin residue for further reuse. Stoichiometric reductive radical reactions with the fluorous tin hydride 3 have been previously reported and a catalytic procedure is also well established. The reduction of adamantyl bromide in BTF (benzotrifluoride) " using 1.2 equiv of the fluorous tin hydride and a catalytic amount of azobisisobutyronitrile (AIBN) was complete in 3 hr (Scheme 1). After the simple liquid-liquid extraction, adamantane was obtained in 90% yield in the organic layer and the fluorous tin bromide was separated from the fluorous phase. The recovered fluorous tin bromide was reduced and reused to give the same results. Phenylselenides, tertiary nitro compounds, and xanthates were also successfully reduced by the fluorous fin hydride. Standard radical additions and cyclizations can also be conducted as shown by the examples in Scheme 1. Hydrostannation reactions are also possible, and these are useful in the techniques of fluorous phase switching. Carbonylations are also possible. Rate constants for the reaction of the fluorous tin hydride with primary radicals and acyl radicals have been measured it is marginally more reactive than tributlytin hydrides. ... 

Curran, P., J. Maul, P. Ostrowski, G. Ublacker, and B. Linclau. 1999. Benzotrifluoride and derivatives Useful solvents for organic synthesis and fluorous synthesis. Topics in Current Chemistry 206 79-105. 

For these reasons, recent investigations have focused on the development of more practical reaction conditions. Bases such as DBU or DBN increase the reaction rate, and the reaction can be performed at room temperature within a few hours in the presence of these additives [12]. The combination of Cu(CH3CN)4BF4 as catalyst and benzotrifluoride as solvent enables the reaction to be conducted without excess olefin in good yields and short reaction times [13]. Recyclable catalysts have also been developed. Fluorous [14] or water-soluble catalysts [15] and Cu-exchange zeolites [16] can be reused and enable several catalytic cycles without loss of activity. 

Reactions in fluorous solvents (usually perfluorinated hydrocarbons) have been described [65], and benzotrifluoride (PhCF3) has shown to be a useful replacement for CH2C12 [66], These solvents are significantly more expensive than solvents routinely used today, but prices may drop as applications and demand rise. 

Benzotrifluoride (C HsCFj) or BTF is a partially fluorinated solvent that dissolves both fluorous-and purely organic molecules. 

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