2.2.2- Trifluoro- -ethanol

Beilstein Handbook Reference) AI3-25486 BRN 1733203 EINECS 200913-6 Ethanol, 2,2,2-trifluoro- Fluorinol 85 NSC 451 TFE Trifluoro-ethanol p,p,p-Trifluoroethyl alcohol 2,2,2-Trifluoroethyl alcohol. Used in synthetic chemistry and as a coating for metals in the automobile industry. Liquid mp = 43.5 bp b 74 d = 1.3842 soluble in EtOH, less soluble in con-polar solvents. American Nicketoid Co. Lancaster Synthesis Co. Sigma-Aldrich Fine Chem. Solvay America Inc. 

FIGURE 1 8 Electrostatic potential maps of ethanol and 2 2 2 tnfluoroethanol As indi cated by the more blue less green color in the region near the OH proton in 2 2 2 trifluoro ethanol this proton bears a greater degree of positive charge and is more acidic than the OH proton in ethanol... 

Fig. 13. CD-spectra of random and alternating (L-Leu, L-Lys) u2, u(. a) in water b) in trifluoro-ethanol...

The Separation of the 2,2,2-trifluoro-l-(9-anthryl) Ethanol Isomers by Mixed Interactions... 

We have seen that the spectra of enantiomers, acquired under normal conditions, are identical. The NMR spectrometer does not differentiate between optically pure samples, and racemic ones. The wording is carefully chosen, particularly normal conditions , because it is often possible to distinguish enantiomers, by running their spectra in abnormal conditions - in the presence of a chiral resolving agent. Perhaps the best known of these is (-)2,2,2,trifluoro-l-(9-anthryl) ethanol, abbreviated understandably to TFAE. (W.H. Pirkle and D.J. Hoover, Top. Stereochem., 1982,13, 263). Structure 7.4 shows its structure. 

By the way, trifluoroacetaldehyde is a versatile fluoro building block. However the chemical or electrochemical oxidative transformation of trifluoro-ethanol to trifluoroacetaldehyde has been unsuccessful. Trifluoroacetaldehyde is therefore generally produced by the reduction of trifluoroacetic acid ester or acid chloride using an excess of LAH. The anodic substitution at fluoroaikyl phenyl sulfides is a useful alternative because it realizes the transformation of economical trifluoroethanol to highly valuable trifluoroacetaldehyde equivalents as shown in Scheme 6.5. 

The CSAs that have been used most widely are 2,2,2-trifluoro-l-phenylethanol (TFPE, la), 2,2,2-trifluoro-l-(l-naphthyl)ethanol (TFNE, lb), 2,2,2-trifluoro-l-(9-anthryl)ethanol (TFAE, Ic), 1-phenylethylamine (PEA, 2a), and l-(l-naphthyl)ethylamine (NEA, 2b). Both enantiomers of TFPE, TFAE (9), PEA, and NEA are commercially available. The fluoroalcohols are relatively acidic and interact strongly with solutes having one or more basic sites (Sect. IV-B). Amines 2 have been used most often as CSAs for organic acids or other acidic solutes (Sect. IV-C). A number of analogs of TFAE have been studied (Sect. III-C). 

NELjAc, ammonium acetate Npg, a-neopentyl-glycine DNZ, 3,5-dinitrobenzyloxycarbonyl Z, ben-zyloxycarbonyl Bz, benzoyl Ac, acetyl TFAE, 2,2,2-trifluoro-l-(9-anthryl)-ethanol IPP, 1-phenyl-propanol 2PP, 2-phenylpropanol 3CPP, 3-chloro-l-phenylpropanol ACN, acetonitrile EA, ethyl acetate. 

Utilization of fluoroalkyl-substituted dicarbonyl compounds is accompanied with side reactions. Trifluoro diketone 49 undergoes an acidic Claisen cleavage in ethanol with formation of dicyanoketone 50, which... 

The transmetallation of the lithiated anion, generated from the tosylate of trifluoro-ethanol, is performed at low temperature with a borane or with cyclopentadienylzir-conium. A further transmetallation affords a second organometallic species that is more stable or more reactive (zinc or copper) and that has a broader synthetic potential... 

Synthesis The condensation of 4-methylacetophenone with ethyl acetate by means of NaOMe in refluxing methanol gives 4,4,4-trifluoro-1-(4-methylphenyl)butane-1,3-dione, which cyclized with 4-hydrazinophenyl-sulfonamide in refluxing ethanol (Graul et al., 1977 Talley et al. (Searle Co.), 1995. 

The hydrogen-bonding association of amino acid esters with l-phenyl-2,2,2-trifluoro-ethanol is sufficient to permit NMR to be used as a method for determining the optical purities of a-amino acids [43],... 

Ethanole t-(2-(Mcthoxy-methoxy)-phenyl]-2,2,2-trifluoro- E10b2,... 

Ethanole 1.1-Bis-[diphenylphos-phano]-trifluoro- ElOb,. 681 (Ai2PO-CO-CF3 +... 

S)-(-)-2-Methyl-1 -butanol (GC purity > 99.5% [a]p -6.6 0.3° (ethanol, c 10) was purchased from Fluka Chemie AG. Esterification with (R)-(+)-3.3,3-trifluoro-2-methoxy-2-phenylpropionic acid (Mosher s acid)2 and subsequent fH and 19F NMR analyses at 300 MHz of the resulting ester showed an enantiomeric purity of (S)-(-)-2-methyl-1-butanol > 99%. 

Measured in a mixture of CHCI3 and 2,2,2-trifluoro-ethanol (9/1, v/v). "Determined by GPC of poly(MMA) derived from poly(D2PyM A). 

---