Fluorinated heterocyclic compounds: an assay on the photochemistry of some fluorinated 1-oxa-2-azoles: an expedient route to fluorinated heterocycles
作者:Silvestre Buscemi、Andrea Pace、Ivana Pibiri、Nicolò Vivona、Tullio Caronna
DOI:10.1016/j.jfluchem.2003.07.006
日期:2004.2
Photoinduced heterocyclic rearrangements of ON bond-containing azoles have been claimed in the synthesis of target fluorinated heterocyclic compounds. In this context, the photochemical behavior of some fluorinated 1,2,4-oxadiazoles has been investigated. Irradiations of 3-amino-5-perfluoroalkyl-1,2,4-oxadiazoles at λ=313 nm in methanol gave open-chain products arising from a reaction of the nucleophilic
在目标氟化杂环化合物的合成中,已要求保护含ON键的唑的光诱导杂环重排。在这种情况下,已经研究了一些氟化的1,2,4-恶二唑的光化学行为。3-氨基-5-全氟烷基-1,2,4-恶二唑在λ处的辐照在甲醇中= 313nm时,产生了由亲核溶剂与首先形成的环状光解物质或由其产生的腈亚胺部分的反应产生的开链产物。不同的是,在三乙胺(TEA)存在下在甲醇中辐照遵循竞争性的光移位途径,导致环状异构体2-氨基-5-全氟烷基-1,3,4-恶二唑(主要成分)和环状简并异构体5-氨基-3-全氟烷基-1,2,4-恶二唑(次要组分)。另一方面,当在λ= 254nm下进行照射时,将3-氨基-5-聚氟苯基-1,2,4-恶二唑进行环光异构化为1,3,4-恶二唑。反过来,在λ处辐照3-苯基-5-全氟庚基-1,2,4-恶二唑在甲醇中= 254nm给出溶剂分解产物,但是未观察到环异构化。报告了一些机械方面的考虑,并要求保护在合成目标氟化1