Synthesis and Structure of Environmentally Relevant Perfluorinated Sulfonamides.
Synthesis and Structure of Environmentally Relevant Perfluorinated Sulfonamides.
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DOI：
10.1016/j.jfluchem.2007.01.013
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发表时间：
2007-06
影响因子：
1.9
通讯作者：
H. Lehmler;V. R. Rama Rao;D. Nauduri;J. Vargo;S. Parkin
中科院分区：
文献类型：
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作者：
H. Lehmler;V. R. Rama Rao;D. Nauduri;J. Vargo;S. Parkin
烷基化全氟辛烷磺酰胺是环境问题化合物。为了使这些化合物可用于环境和毒理学研究，通过相应的全氟烷基磺酰氟与合适的伯胺或仲胺反应合成了一系列N-烷基化全氟辛烷磺酰胺和结构相关的化合物。N-烷基全氟烷基磺酰胺可直接与溴乙醇烷基化或与乙酸2-溴乙酯烷基化后水解得到全氟烷基磺酰胺基乙醇。N-烷基全氟辛烷磺酰胺基乙酸酯以类似的方式通过N-烷基全氟烷烃磺酰胺与溴乙酸酯的烷基化，然后通过碱性酯水解来合成。或者，N-烷基全氟烷磺酰胺可以使用Mitsunobu反应用适当的醇烷基化。以全氟辛基磺酰氟为原料，经Zn/HCl还原，得到叠氮化物，再经氯化还原得到全氟辛基磺酰胺。所有的全氟辛烷磺酰胺都含有线性和支化的C8 F17异构体，通常比例为10：1至30：1。N-乙基全氟辛烷磺酰胺和N，N-二乙基全氟辛烷磺酰胺的晶体结构表明，S-N键具有明显的双键特征。这种双键特性导致围绕S-N键的显著旋转势垒（ΔG =62- 71 kJmol −1）和优选的固态和溶液构象，其中N-烷基与全氟辛基相反取向以使围绕S-N键的空间拥挤最小化。
Alkylated perfluorooctanesulfonamides are compounds of environmental concern. To make these compounds available for environmental and toxicological studies, a series of N-alkylated perfluorooctanesulfonamides and structurally related compounds were synthesized by reaction of the corresponding perfluoroalkanesulfonyl fluoride with a suitable primary or secondary amine. Perfluoroalkanesulfonamidoethanols were obtained from the N-alkyl perfluoroalkanesulfonamides either by direct alkylation with bromoethanol or alkylation with acetic acid 2-bromo-ethyl ester followed by hydrolysis of the acetate. N-Alkyl perfluorooctanesulfonamidoacetates were synthesized in an analogous way by alkylation of N-alkyl perfluoroalkanesulfonamides with a bromo acetic acid ester, followed by basic ester hydrolysis. Alternatively, N-alkyl perfluoroalkanesulfonamides can be alkylated with an appropriate alcohol using the Mitsunobu reaction. Perfluorooctanesulfonamide was synthesized from the perfluorooctanesulfonyl fluoride via the azide by reduction with Zn/HCl. All perfluorooctanesulfonamides contained linear as well as branched C8F17isomers, typically in a 10:1 to 30:1 ratio. The crystal structures of N-ethyl and N,N-diethyl perfluorooctanesulfonamide show that the S–N bond has considerable double bond character. This double bond character results in a significant rotational barrier around the S–N bond (ΔG≠=62–71kJmol−1) and a preferred solid state and solution conformation in which the N-alkyl groups are oriented opposite to the perfluorooctyl group to minimize steric crowding around the S–N bond.