【摘要】 以3-氧杂多氟烷烃磺酰氟XOCF₂CF₂SO₂F为原料,在二氯甲烷中于-20～-30C°与三乙胺、含氟醇或苯酚反应得到一系列氧杂多氟磺酸酯XOCF₂CF₂SO₃R（1a～1g）,产率52～90％.影响产率的主要因素是反应温度,而不是碱用量.亲核试剂与这些磺酸酯作用,主要引起酯基的C—O断裂.如1a或1c与I^,CNS和R¹R²NH反应得HCF₂CF₂CH₂Y（Y=I,CNS,R¹R²N）,与HCF₂CF₂CH₂O^得对称醚（HCF₂CF₂CH₂）₂O.与前人不同的是C₂H₅O^,CH₃OCH₂CH₂O^和C₆H₅O^对1a或1c都以C—O断裂为主,而1f与HCF₂CF₂CH₂O^的反应似乎是发生了S—O断裂.首次研究了氟碳烷氧基阴离子R_FCF₂O^[FO₂SCF₂CF₂O^,（CF₃）₂CFO^,n-C₃F₇OCF（CF₃）CF₂O^,FO₂SCF₂CF₂OC₂CF₂O^和Cl（CF₂）₅CF₂O^]对1a和1c的亲核取代,所得产物的结构与R_FCOF+F^→←R_FCF₂O^平衡中R_FCF₂O^的生成量和溶解度有关.在HMPA中为均相反应,产物以R_FCF₂OCH₂CF₂CF₂H为主;在DMSO中反应液和固体不互溶,羧酸酯为主要产物;若以DMF为溶剂,则可以是酯亦可以是醚;以DG为溶剂时,虽然混合液体不互溶,但仍以C—O断裂为主.可能的解释是在高介电常数的非质子性溶剂中（如DMSO,DMF）,溶剂参与了反应,促使磺酸酯发生S—O断裂,生成的^OCH₂R’与酰氟作用而得酯.由于DG的低介电常数,亲核试剂仍以引起C—O断裂为主而得醚.当无氟化钾时,1a或1c在DG中并不与R_FCOF反应,但在DMSO,DMF,HMPA中却得酯,也符合于溶剂效应的假设,即溶剂参与反应,促使磺酸酯发生S—O断裂,生成的HCF₂CF₂CH₂O^再与酰氟发生酯化.全氟α-正丙氧基丙酸钠在DMSO,DMF,DG中或其酸在DMSO中亦均能与1a成酯.估计其机理不同于以R_FCOF为原料者,前者是简单的亲核取代,而后者可能是溶剂参与了反应,因为全氟羧酰氟与氟化钾在DMSO作用下,得不到相应的羧酸阴离子.更多还原

【Abstract】 α,α,ω-Tri-H-perfluoroalkyl and phenyl 3-oxapolyfluoroalkanesulfonates XOCF₂CF₂SO₃R[R=HCF₂CF₂CH₂: X=ICF₂CF₂（1a）, CH₃（1b）,Cl₂CFCF₂（1c）, HCF₂CF₂CH₂（1d）; R=H（CF₂CF₂）₂CH₂: X=Cl₂CFCF₂（1e）; R=C₆H₅: X=ICF₂CF₂（1f）; Cl₂CFCF₂（1g）] were synthesized by the reactions of 3-oxaperfluoroalkanesulfonyl fluorides with 1,1,3-tri-H-tetrafluoropropanol, 1,1,5-tri-H-perfluoropentanol and phenol respectively in 50～90% yields. The main factor affecting the yield of the sulfonates was the reaction temperature, not the amount of base used. The sulfuroxygen and/or carbon-oxygen scissions can occur in these sulfonates during nucleophilic substitution. For example, sulfonates 1a or 1c was attacked by I, CNS and R¹R²NH only at the alkyl carbon with C-O bond scission giving the derivatives, HCF₂CF₂CH₂Y（Y=I, CNS, R¹R²N）. Symmetrical ether was obtained from the reaction of 1a or 1c with polyfluoroalkoxide HCF₂CF₂CH₂O. In contrast to the result previously reported the reaction of C₂H₅O, CH₃OCH₂CH₂O and C₆H₅O with 1a or 1c yielded mainly ethers showing the dominant occurrence of C-O cleavage. Whereas the reaction of HCF₂CF₂CH₂O with 1f seems to proceed via a S-O cleavage route only. Perfluoroalkoxide ion formed from the corresponding acid fluoride or ketone with fluoride ion[FO₂SCF₂CF₂O,（CF₃）₂CFO, n-C₃F₇OCF（CF₃）CF₂O, FO₂SCF₂CF₂OCF₂CF₂O, Cl（CF₂）₃CF₂O] can react successfully with sulfonates 1a and 1c. The structure of the product obtained depended on the amounts of R_FCF₂O formed and its solubility in the solvent in the following reversible equilbrium.In HMPA, the reaction mixture forms a homogeneous system, the ethers R_FCF₂OCH₂CF₂CF₂H being the main products. In DMSO, the reactants and solvents are not completely miscible and solid KF is always present, the esters R_FCO₂CH₂CF₂CF₂H being obtained predominantly. In DMF, the product may be ether or ester. In DG, in spite of the heterogeneity of the reacting system, C-O scission predominated. A possible interpretation is that in the aprotic solvents with high dielectric constant（such as DMSO, DMF）, the solvent molecules may participate in an initial S-O scission, followed by the attack of the resulting R’_FCH₂O on acyl fluoride to give the ester. In DG, due to its low dielectric constant, nucleophile effects only C-O scission to form ether. This is in agreement with the finding that in the absence of KF, 1a or 1c did react with R_FCFO in DMSO, DMF and HMPA to give ester, whereas in DG, no reaction was observed between 1a or 1c with R_FCFO. Both sodium perfluoro-α-propyloxy propionate in DMSO, DMF or DG and the free acid in DMSO can undergo reaction with 1a giving ester 11. Probably the mechanism is not identical with that in the case of using acyl fluoride as starting material. In the former it is a simple nucleophilic substitution, in the latter the solvent may participate in the reaction, because the reaction of perfluoroacyl fluoride with potassium fluoride in DMSO does not yield the corresponding carboxylate anion.更多还原