Iron(III) Chloride/Dialkyl Diselenides‐Promoted Cascade Cyclization of
<i>ortho</i>
‐Diynyl Benzyl Chalcogenides
作者:Roberto do Carmo Pinheiro、Davi F. Back、Gilson Zeni
DOI:10.1002/adsc.201900086
日期:2019.4.16
Treatment of ortho‐diynyl benzyl chalcogenides with a mixture of iron(III) chloride and diorganyl diselenides led to functionalized chalcogen isochromene‐fused chalcogenophene derivatives. The reaction parameters were studied and the results indicated that the reaction of ortho‐ diynyl benzyl chalcogenides (0.25 mmol) with iron(III) chloride hexahydrate (2.0 equiv.) and diorganyl diselenide (2 equiv
We present here our results on the preparation of 2-alkynylbenzyl selenide and sulfide derivatives via Sonogashira cross-coupling of benzyl chalcogenides with different alkynes. This cross-coupling reaction proceeded cleanly under mild conditions and was performed with propargyl alcohol as well as alkyl- and arylalkynes. Subsequent electrophilic-cyclization reaction of the 2-alkynylbenzyl selenide and sulfide derivatives using iodine as an electrophilic source gave 4-iodo-3-substituted 1H-isoselenochromenes and -isothiochromenes in moderate yields. The unique product obtained during the course of this cyclization contained a six-membered ring which was confirmed by X-ray diffraction analysis.
我们在此介绍通过苄基卤化物与不同炔烃的 Sonogashira 交联反应制备 2-炔苄基硒化物和硫化物衍生物的研究成果。这种交叉偶联反应在温和的条件下进行,并可与丙炔醇以及烷基和芳基炔进行反应。以碘为亲电源,2-炔苄基硒化物和硫化衍生物随后发生亲电环化反应,以中等产率得到了 4-碘-3-取代的 1H-异硒二苯并二氢吡喃和异二苯并二氢吡喃。这种环化过程中得到的独特产物含有一个六元环,并通过 X 射线衍射分析得到了证实。