FACILE SYNTHESIS OF FLUORINATED PHOSPHONATES VIA PHOTOCHEMICAL AND THERMAL-REACTIONS

Under UV irradiation (254 nm) at ambient temperature, a degassed mixtu re of (EtO)(2)POP(OEt)(2) and RfI {R-f=CF3, C2F5, C4F9, C6F13, (CF3)(2 )CF, CF2CF=CF2, ClCF2CF2, BrCF2CF2, C6F5, ClCF2CFClCF2CF2, I(CF2)(3), I(CF2)(4), FO2S(CF2)(4), FO2S(CF2)(2)O(CF2)(2)} affords the fluorinate d phosphonite, [RfP(OEt)(2)]. Oxidation of the phosphonites, [RfP(OEt) (2)], with Me3COOH gave the corresponding fluorinated phosphonates, (E tO)(2)P(O)R-f(1-14), in 35-80% isolated yields. CF3CCl2I reacts with ( EtO)(2)POP(OEt)(2) at room temperature in the absence of UV irradiatio n to afford [CF3CCl2P(OEt)(2)] which upon oxidation gave a 52% yield o f CF3CCl2P(O)(OEt)(2) (15). The reaction of (EtO)(2)POP(OEt)(2) and Rf I (R-f=ClCF2CF2, BrCF2CF2, C2F5) at 125 degrees C in the presence of M e3COOCMe3 and subsequent oxidation of the resultant phosphonites affor ded phosphonates (2, 7, and 8) albeit in lower yields (49-62%) compare d to those of the photochemical reaction (58-80%). (RO)(2)P(O)CF2CF2I (R=Et, i-Pr) (16 and 17) was obtained (42-48%) when a degassed mixture of (RO)(3)P and BrCF2CF2I was subjected to UV irradiation (254 nm) at ambient temperature via a unique photochemical transformation.