Fluoroethanols

Difluoroethanol [359-13-7], F2CHCH2OH, is a colorless Hquid with an alcohol-like odor mp, 28.2°C, bp, 96°C d[, 1.3084 n], 1.3320 heat of combustion, —1026 kJ/mol(—245.3 kcal/mol). It is stable to distillation and miscible with water and many organic solvents. As expected, its acidity Hes between that of 2-fluoroethanol and 2,2,2-trifluoroethanol both ia the gas phase (25) and ia 50% aqueous ethanol solution (26), where its of 1.0 x 10 is about 4.8 times smaller than that of trifluoroethanol. 

H2Br (bromoethanol) > —H2CH3 (propanol) > H2C1 (chloroethanol) > Fj (tri-fluoroethanol) > —H2F (fluoroethanol) > —H3 (ethanol)... 

Toxic compounds that can be absorbed to a marked degree by a living plant through either its roots or its leaves have been called by British investigators systemic insecticides. Schrader (38) first found this peculiar property in certain acetals of 2-fluoroethanol and bis-(2-fluoroethoxy) methane, as well as in certain compounds of his organic phosphorus series, notably bis(dimethylamido)fluophosphate and octamethyl pyrophosphoramide. 

Regarding proton spectra, as was the case with 2,2,2-trifluoroethyl chloride (Scheme 5.7), the chemical shifts of the CH2 protons of 2,2,2-tri-fluoroethanol and of 2,2,2-trifluoroethyl ethers are more affected by the OH or ether substituents than they are by the CF3 group. 

A catalytic asymmetric amination reaction has been developed using Cu(2+) catalysts (246). The azodicarboxylate derivative 392 reacts with enolsilanes in the presence of catalyst 269c to provide the adducts in high enantioselectivity, Eq. 213. As observed in the Mukaiyama Michael reactions, alcoholic addends proved competent in increasing the rate of this reaction. Indeed, in the presence of tri-fluoroethanol as additive, the reaction time decreases from 24 to 3 h. 

---