Kondoh Azusa, Aita Kohei, Ishikawa Sho, Terada Masahiro
Research and Analytical Center for Giant Molecules, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
Org Lett. 2020 Mar 6;22(5):2105-2110. doi: 10.1021/acs.orglett.0c00619. Epub 2020 Feb 25.
An efficient method for the synthesis of tetrasubstituted furans was developed by utilizing the [1,2]-phospha-Brook rearrangement under Brønsted base catalysis. The two-step one-pot formal [3 + 2] cycloaddition involves the nucleophilic addition of a propargyl anion, which is catalytically generated through the [1,2]-phospha-Brook rearrangement, to an aldehyde and the subsequent intramolecular cyclization mediated by -iodosuccinimide to provide 2,4,5-trisubstituted-3-iodofurans. The present method with readily available substrates provides new access to a wide range of well-organized tetrasubstituted furans.
通过在布朗斯特碱催化下利用[1,2]-磷杂-Brook重排反应，开发了一种高效合成四取代呋喃的方法。该两步一锅法形式上的[3 + 2]环加成反应包括，通过[1,2]-磷杂-Brook重排反应催化生成的炔丙基阴离子对醛的亲核加成，以及随后由N-碘代琥珀酰亚胺介导的分子内环化反应，以提供2,4,5-三取代-3-碘代呋喃。该方法使用易于获得的底物，为多种结构规整的四取代呋喃提供了新的合成途径。
