Facile Synthesis of Fluorinated Phosphonates via Photochemical and Thermal Reactions

• Published in: Journal of the American Chemical Society Vol. 119; no. 39; pp. 9137 - 9143
• Main Authors: Nair, Haridasan K, Burton, Donald J
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 01.10.1997; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Multidisciplinary; Physical Sciences; Science & Technology; GLYCEROL-3-PHOSPHATE DEHYDROGENASE; ELECTRON-TRANSFER; DIFLUOROMETHYLENEPHOSPHONATE ANALOGS; SOLID-PHASE SYNTHESIS; PURINE NUCLEOSIDE PHOSPHORYLASE; DIFLUOROPHOSPHONOACETIC ACID; X-RAY STRUCTURE; MULTISUBSTRATE ANALOG INHIBITORS; O-PHOSPHOTYROSINE; ALPHA,ALPHA-DIFLUORO FUNCTIONALIZED PHOSPHONATES
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja971345t

Under UV irradiation (254 nm) at ambient temperature, a degassed mixture of (EtO)2POP(OEt)2 and RfI {Rf = CF3, C2F5, C4F9, C6F13, (CF3)2CF, CF2CFCF2, ClCF2CF2, BrCF2CF2, C6F5, ClCF2CFClCF2CF2, I(CF2)3, I(CF2)4, FO2S(CF2)4, FO2S(CF2)2O(CF2)2} affords the fluorinated phosphonite, [RfP(OEt)2]. Oxidation of the phosphonites, [RfP(OEt)2], with Me3COOH gave the corresponding fluorinated phosphonates, (EtO)2P(O)Rf (1−14), in 35−80% isolated yields. CF3CCl2I reacts with (EtO)2POP(OEt)2 at room tempearture in the absence of UV irradiation to afford [CF3CCl2P(OEt)2] which upon oxidation gave a 52% yield of CF3CCl2P(O)(OEt)2 (15). The reaction of (EtO)2POP(OEt)2 and RfI (Rf = ClCF2CF2, BrCF2CF2, C2F5) at 125 °C in the presence of Me3COOCMe3 and subsequent oxidation of the resultant phosphonites afforded phosphonates (2, 7, and 8) albeit in lower yields (49−62%) compared to those of the photochemical reaction (58−80%). (RO)2P(O)CF2CF2I (R = Et, i-Pr) (16 and 17) was obtained (42−48%) when a degassed mixture of (RO)3P and BrCF2CF2I was subjected to UV irradiation (254 nm) at ambient temperature via a unique photochemical transformation.