THE CHEMO-SELECTIVE REDUCTION OF FLUORINATED HALOGENOESTERS WITH SODIUM BOROHYDRIDE. FLUORINATED HALOGENOALKANOLS AND THEIR (METH)ACRYLATES

Article abstract of DOI:10.1016/S0022-1139(00)82869-9

Several chlorofluoroalkanols R_F-CH2OH (R_F is CF3-CFCl, CF2Cl-CF2, CF2Cl-CFCl and CF2Cl) and their methacrylates or acrylates were synthesized.The corresponding polymeric methacrylates have properties of highly-sensitive electron-beam and X-ray resists for microlithography.The main step in the syntheses, which start from halogenoalkanes R_F-CCl3, is the chemo-selective reduction of halogenoesters with sodium borohydride, in which the C-Cl bonds in the acyl parts of the esters are not attacked.Relative rates of the reductions of esters R_F-COOCH3 are influenced by the structure of halogenoalkyls R_F in the order CF2Cl: CF3-CFCl: CF2Cl-CFCl = 4.5:3.5:1.A remarkable reactivity decrease in the reduction rate in the structure possessing a Cl atom at the β-position in the acyl group is discussed.