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Synthetic Methods for High-Energy Organofluorine Compounds
Published in Mark J. Mezger, Kay J. Tindle, Michelle Pantoya, Lori J. Groven, Dilhan M. Kalyon, Energetic Materials, 2017
Dolbier developed new synthetic methodologies to introduce the SF5-moiety into the furazan-containing high-energy materials and showed that these derivatives have relatively higher energy densities and detonation properties than the corresponding unsubstituted furazans.28 Free radical addition of SF5Cl (bp 6°C) to vinyl acetate (48), initiated by triethylborane (Et3B), proceeds at low temperature (−45°C) to give the corresponding addition product, (2-pentafluorosulfanyl-1-chloroethyl)acetate (93% yield), which upon methanolysis at 50°C gives the 2-pentafluorosulfanylacet aldehyde dimethyl acetal (49).36 Oxidation of the latter compound using Caro’s acid (peroxymonosulfuric acid) under mild reaction conditions then gives methyl pentafluorosulfanylacetate (50), which could be further transformed into its corresponding carboxylic acid (51; alkaline hydrolysis) and acid chloride derivatives (52; halide exchange of the carboxylic acid using benzoyl chloride) (Figure 1.16).32 The latter compounds are useful as the starting materials for SF5 functionalization of the amino groups in the amino-substituted furazans.
Thermochemistry, Electrochemistry, and Solution Chemistry
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
1-Tridecanol 1-Tridecene Triethanolamine Triethylamine Triethylborane Triethylene glycol Trifluoroacetic acid Trifluoroacetonitrile 1,1,1-Trifluoroethane 1,1,2-Trifluoroethane 2,2,2-Trifluoroethanol Trifluoroethene 1,1,1-Trifluoro-2-iodoethane Trifluoroiodomethane Trifluoromethane Trifluoromethyl (Trifluoromethyl)benzene 1,1,1-Trifluoro-2,4pentanedione 3,3,3-Trifluoro-1-propene Trifluorosilane Trigermane Trihexylamine Trihydro(phosphorus trifluoride)boron Triiodomethane Trimethyl aluminum Trimethylamine Trimethylamine borane Trimethylamine hydrochloride 1,2,3-Trimethylbenzene 1,2,4-Trimethylbenzene 1,3,5-Trimethylbenzene Trimethylborane Trimethyl borate 2,2,3-Trimethylbutane 2,3,3-Trimethyl-1-butene Trimethylchlorosilane 1,3,5-1,3,5-Trimethylcyclohexane 1,1,2-Trimethylcyclopropane 2,2,3-Trimethylhexane 2,2,4-Trimethylhexane 2,2,5-Trimethylhexane 2,3,3-Trimethylhexane 2,3,5-Trimethylhexane 2,4,4-Trimethylhexane 3,3,4-Trimethylhexane Trimethylolpropane 2,2,3-Trimethylpentane 2,2,4-Trimethylpentane 2,3,3-Trimethylpentane 2,3,4-Trimethylpentane 2,2,4-Trimethyl-3-pentanone 2,4,4-Trimethyl-1-pentene 2,4,4-Trimethyl-2-pentene Trimethylsilane Trimethylurea Trinitroacetonitrile 1,3,5-Trinitrobenzene 2,4,6-Trinitro-1,3benzenediol Trinitroglycerol Trinitromethane 2,4,6-Trinitrophenol 2,4,6-Trinitrotoluene
Hydro-trifluoromethyl(thiol)ation of alkenes: a review*
Published in Journal of Sulfur Chemistry, 2022
Seyedeh Bahareh Azimi, Manzarbanou Asnaashariisfahani, Bayan Azizi, Elham Mohammadi, Abdol Ghaffar Ebadi, Esmail Vessally
After pioneering work by Czekelius and colleagues on Yb(OTf)3·nH2O mediated hydrotrifluoromethylation of a small library of α,β-unsaturated acyl-oxazolidinones employing trifluoroiodomethane (CF3I) as source of the trifluoromethyl group and the merge of triethylborane (Et3B) and oxygen as the radical initiator [63], the first efficient and practical methodology for the direct hydrotrifluoromethylation of C–C double bonds with CF3I was published in 2014 by Choi et al [64]. In this investigation, six (3,3,3-trifluoropropyl)arenes 22 were efficiently synthesized through the treatment of respective styrene derivatives 21 with CF3I in the presence of 3 equiv. of an inorganic electride, [Ca2N]+•e−, in EtOH/MeCN at room temperature (Scheme 13). Interestingly, the electronic effects of the substituents on the aromatic units had no significant impact on the success of this reaction. Thus, styrenes bearing both electron-donating and electron-withdrawing groups were well tolerated under the reaction conditions. Of note, the identical condition was also effective for mono-selective hydrotrifluoromethylation of terminal alkynes. The authors found that the amount of electride played an important role in this reaction. Interestingly, when the amount of [Ca2N]+•e− was decreased to 1.5 equiv., α-iodo-β-CF3 styrenes were formed as the sole products. The plausible mechanistic pathway for the hydrotrifluoromethylation of alkenes is illustrated in Scheme 14. In the beginning, a SET from [Ca2N]+•e− to CF3I results in the formation of the CF3 radical that after regioselective addition to the styrene 21 generates benzyl radical X. Later on, the second SET from [Ca2N]+•e− to the newly formed radical X forms the carbon anion intermediate XI. Finally, this intermediate would abstract a hydrogen from EtOH to yield the target product 22 (Scheme 14, path a). In another possibility, the direct abstraction of a hydrogen from O-H or α-C–H bond of ethanol affords the expected hydrotrifluoromethylated product 22 (Scheme 14, path b).