Formation of Condensed 1<i>H</i>-Pyrrol-2-ylphosphonates and 1,2-Dihydropyridin-2-ylphosphonates via Kabachnik–Fields Reaction of Acetylenic Aldehydes and Subsequent 5-<i>exo</i>-<i>dig</i> or 6-<i>endo</i>-<i>dig</i> Cyclizations
作者:Rita Bukšnaitienė、Aurelija Urbanaitė、Inga Čikotienė
DOI:10.1021/jo501011u
日期:2014.7.18
Kabachnik–Fields reactions of various carbocyclic or heterocyclic acetylenic aldehydes together with subsequent Lewis acid catalyzed cyclizations have been studied. It was found that 5-exo-dig versus 6-endo-dig cyclization mode strongly depends on the structure of starting materials. Thus, nonaromatic acetylenic α-anilinomethylphosphonates underwent gold(III)-catalyzed or iodine-mediated 5-exo-dig
研究了各种碳环或杂环炔醛的Kabachnik-Fields反应以及随后的路易斯酸催化的环化反应。发现5- exo - dig与6- endo - dig环化模式在很大程度上取决于起始材料的结构。因此,非芳族炔属α-苯胺基甲基膦酸酯经历了金(III)催化或碘介导的5- exo - dig环化成1 H-吡咯-2-基膦酸酯。与此相反,吸电子的杂芳族的基体构成通过专用6-含材料-1,2-二氢吡啶-2- ylphosphonate环内-挖闭环过程。仅对于含有苯环的α-氨基(2-炔基苯基)甲基膦酸酯,双环化是可能的。