Synthesis of 5-Iodobenzofurans and 6-Iodobenzopyrans via Direct Iodination with Mercury(II) Oxide-Iodine Reagent
作者:Kazuhiko Orito、Takahiro Hatakeyama、Mitsuhiro Takeo、Hiroshi Suginome、Masao Tokuda
DOI:10.1055/s-1997-1504
日期:1997.1
A tin(IV) chloride assisted iodo-cyclization of 2-allylphenol gave 2-iodomethyl-2,3-dihydrobenzofuran. A similar cyclization of 2-crotylphenol gave 3-iodo-2-methyl-3,4-dihydro-2H-benzopyran, exclusively. By iodination with mercury(II) oxide-iodine reagent in dichloromethane, 2,3-dihydrobenzofurans or 3,4-dihydro-2H-benzopyrans including the above benzocyclic ethers were easily converted to the corresponding 5- or 6-iodo derivatives, regioselectively, in good yield.
在氯化锡(IV)的辅助下,2-烯丙基苯酚发生碘环化反应,生成 2-碘甲基-2,3-二氢苯并呋喃。对 2-烯丙基苯酚进行类似的环化反应,只能得到 3-碘-2-甲基-3,4-二氢-2H-苯并呋喃。用二氯甲烷中的氧化汞-碘试剂进行碘化,包括上述苯环醚在内的 2,3-二氢苯并呋喃或 3,4-二氢-2H-苯并吡喃很容易被转化成相应的 5-或 6-碘衍生物,且具有良好的区域选择性。