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以3-氧杂多氟烷烃磺酰氟XOCF_2CF_2SO_2F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XOCF_2CF_2SO_3R(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R~1R~2NH反应得HCF_2CF_2CH_2Y(Y=I,CNS,R~1R~2N),与HCF_2CF_2CH_2O~得对称醚(HCF_2CF_2CH_2)_2O.与前人不同的是C_2H_5O~,CH_3OCH_2CH_2O~和C_6H_5O~对1a或1c都以C—O断裂为主,而1f与HCF_2CF_2CH_2O~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_FCF_2O~[FO_2SCF_2CF_2O~,(CF_3)_2CFO~,n-C_3F_7OCF(CF_3)CF_2O~,FO_2SCF_2CF_2OC_2CF_2O~和Cl(CF_2)_5CF_2O~]对1a和1c的亲核取代,所得产物的结构与R_FCOF+F~→←R_FCF_2O~平衡中R_FCF_2O~的生成量和溶解度有关.在HMPA中为均相反应,产物以R_FCF_2OCH_2CF_2CF_2H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~OCH_2R’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HCF_2CF_2CH_2O~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.
A series of oxypolyfluorosulfonates XOCF_2CF_2SO_3R were obtained from 3-oxa polyfluoroalkane sulfonyl fluoride XOCF_2CF_2SO_2F by reaction with triethylamine, fluorine-containing alcohol or phenol in dichloromethane at -20 ~ -30 ° C 1a ~ 1g), the yield of 52 ~ 90% .The main factors affecting the yield of the reaction temperature, rather than the amount of alkali.Phonucleophiles and these sulfonate role, mainly caused by the ester group C-O fracture.As 1a or 1c reacted with HCF_2CF_2CH_2Y (Y = I, CNS, R ~ 1R ~ 2N) and HCF_2CF_2CH_2O ~ (HCF_2CF_2CH_2) _2O. The difference from the previous one is that C_2H_5O ~ The reaction of 1f with HCF_2CF_2CH_2O ~ seems to be the S-O cleavage. However, it was the first time to study the effect of the fluorocarbon alkoxy anions R_FCF_2O ~ [FO_2SCF_2CF_2O ~ (( (CF_3) CF_2O ~ (CF_3) CF_2O ~, CF_2_ (CF_3) CF_2O ~, Cl_2CF_2OC_2CF_2O ~ and CF_2_CF_2O_CF_3] to the nucleophilic substitutions of 1a and 1c. The structures of the obtained products are similar to those of R_FCF_2O ~ Of the yield and solubility of HMPA in the homogeneous reaction, the product to R_FCF_2OCH_2CF_2CF_2H-based; reaction solution and solid immiscible in DMSO, carboxylate as the main If DMF is used as solvent, it can be ester or ether.When DG is used as solvent, although the mixed liquids are immiscible, it is still mainly C-O fracture.The possible explanation is that in the case of high dielectric constant non-ionic Proton solvent (such as DMSO, DMF), the solvent involved in the reaction, prompting S-O Sulfonate break occurs, the resulting ~ OCH_2R ’and the role of fluoride obtained ester. Due to the low dielectric constant DG, nucleophiles The ether was still predominantly caused by the C-O cleavage.1a or 1c did not react with R_FCOF in DG but did not react with DMSO, DMF and HMPA in the absence of potassium fluoride, and was also compatible with the solvent effect Assuming that the solvent is involved in the reaction, the S-O cleavage of the sulfonate occurs and the resulting HCF 2 CF 2 CH 2 O is esterified with the acyl fluoride. Sodium perfluoro-n-propoxy propionate is dissolved in DMSO, DMF, DG or its acid In DMSO are also able to ester with 1a.It is estimated that the mechanism is different from the R_FCOF as raw material, the former is a simple nucleophilic substitution, and the latter may be a solvent involved in the reaction, because perfluorocarboxylic acid fluoride and potassium fluoride in Under the action of DMSO, the corresponding carboxylic acid anion can not be obtained.