Concise Route to 3-Arylisoquinoline Skeleton by Lewis Acid Catalyzed C(sp3)–H Bond Functionalization and Its Application to Formal Synthesis of (±)-Tetrahydropalmatine
摘要:
An expeditious route to furnish an isoquinoline skeleton via hydride shift mediated C-H bond functionalization was developed. In this process, an unusual [1,5]-H shift without the assistance of the adjacent heteroatom took place to produce tetrahydroisoquinoline derivatives in good to excellent chemical yields. The formal synthesis of (+/-)-tetrahydropalmatine was achieved by exploiting this new transformation.
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-TSA-Based DESs as “Active Green Solvents” for Microwave Enhanced Cyclization of 2-Alkynyl-(hetero)-arylcarboxylates: an Alternative Access to 6-Substituted 3,4-Fused 2-Pyranones
An acidic Deep Eutectic Solvent is an alternative environmental‐friendly “active” media for the microwave‐mediated synthesis of 6‐substituted 3,4‐fused 2‐pyranones.
In this paper, we describe the silver triflate/p-toluenesulfonic acid co-catalysed synthesis of seventeen isocoumarins and two thieno[2,3-c]pyran-7-ones starting from 2-alkynylbenzoates and 3-alkynylthiophene-2-carboxylates, respectively. The reaction proceeds with absolute regioselectivity under mild reaction conditions and low catalyst loading, to afford the desired products in good to excellent
在本文中,我们描述了三氟甲磺酸银/对甲苯磺酸共催化合成17个异香豆素和两个由2-炔基苯甲酸酯和3-炔基噻吩-2-羧酸酯组成的噻吩并[2,3 - c ]吡喃-7-,分别。反应在温和的反应条件下和低的催化剂载量下以绝对的区域选择性进行,以良好至极好的收率提供所需的产物。提出了一种可能的反应机理,并得到了同位素交换试验,1 H NMR研究和特别实验的支持。
p-Toluenesulfonic acid-promoted selective functionalization of unsymmetrical arylalkynes: a regioselective access to various arylketones and heterocycles
Regioselective hydration of a wide range of internalalkynes has been afforded in high to good yields by using PTSA in EtOH. The scope of the reaction of alkynes has been delineated. Arylaliphatic alkynes and diarylalkynes were regioselectively hydrated in good to excellent yields and short reaction times when the reaction was achieved under microwave irradiation. Moreover, diarylalkynes, arylenynes
Competition Studies in Alkyne Electrophilic Cyclization Reactions
作者:Saurabh Mehta、Jesse P. Waldo、Richard C. Larock
DOI:10.1021/jo802196r
日期:2009.2.6
toward alkyneelectrophiliccyclizationreactions has been studied. The required diarylalkynes have been prepared by consecutive Sonogashira reactions of appropriately substituted aryl halides and competitive cyclizations have been performed using I2, ICl, NBS and PhSeCl as electrophiles. The results indicate that the nucleophilicity of the competing functional groups, polarization of the alkyne triple
已经研究了各种官能团对炔烃亲电环化反应的相对反应性。所需的二芳基炔已通过适当取代的芳基卤化物的连续 Sonogashira 反应制备,并使用 I 2、ICl、NBS 和 PhSeCl 作为亲电子试剂进行竞争性环化。结果表明,竞争官能团的亲核性、炔烃三键的极化和中间体的阳离子性质是决定这些反应结果的最重要因素。
(Trifluoromethyl)thiolation of 2-Alkynylbenzoates: An Efficient Route to 4-[(Trifluoromethyl)thio]-1<i>H</i>-isochromen-1-ones
作者:Yuewen Li、Guangming Li、Qiuping Ding
DOI:10.1002/ejoc.201402629
日期:2014.8
The incorporation of the (trifluoromethyl)thio group into the isocoumarin scaffold through a Lewis-acid-mediated electrophilic cyclization reaction of 2-(2-alkynyl)benzoates with trifluoromethanesulfanylamide is reported. The transformation proceeds well in the presence of BiCl3 and BF3·Et2O under mild conditions to give 4-[(trifluoromethyl)thio]-1H-isochromen-1-ones regioselectively and in good yields