Synthesis of 3‐Organoselenyl‐2
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‐Coumarins from Propargylic Aryl Ethers via Oxidative Radical Cyclization
作者:Jun‐Dan Fang、Xiao‐Biao Yan、Li Zhou、Yu‐Zhao Wang、Xue‐Yuan Liu
DOI:10.1002/adsc.201801565
日期:2019.4.23
A metal‐free oxidative radical cyclization/selenylation of propargylic arylethers with diaryl diselenides was developed. This protocol provided an alternative method to synthesize 3‐organoselenyl‐2H‐coumarins via the formation of C−Se bond, C−C bond, and C=O bond in one step. Moreover, a broad range of functional groups (such as halogen, aldehyde, ketone, cyano, and nitro group) were tolerated.
basis of a study of the O-phenylation of 3-phenyl-2-propyn-1-ol with diphenyliodonium triflate and t-BuONa, a variety of 4-aryl-3-iodo-2H-benzopyrans were prepared in good to moderate yields in one pot from the reaction of 3-aryl-2-propyn-1-ols with diaryliodonium triflates and t-BuONa, followed by the treatment with N-iodosuccinimide and BF3·OEt2, under transition-metal-free and mild conditions. The formed
Catalytic Cascade Cyclization and Regioselective Hydroheteroarylation of Unactivated Alkenes
作者:Rahul K. Shukla、Atul K. Chaturvedi、Chandra M. R. Volla
DOI:10.1021/acscatal.1c01234
日期:2021.7.2
A Pd(II)-catalyzed directed, regio-controlled hydroheteroarylation of unactivatedalkenes via a cascade intramolecular amino/oxy/carbo-palladation of alkynes followed by cis-migratory insertion of alkenes has been developed for the construction of γ-heteroaryl-substituted carbonyl compounds. 8-Aminoquinoline was employed as a cleavable bidentate directing group to stabilize the nucleopalladated vinylpalladium(II)
通过炔烃的级联分子内氨基/氧/碳钯化,然后顺式迁移插入烯烃,未活化烯烃的 Pd(II) 催化定向、区域控制的氢杂芳基化已被开发用于构建γ-杂芳基取代的羰基化合物。8-氨基喹啉用作可切割的双齿导向基团以稳定核钯化乙烯基钯 (II) 中间体,并控制碳钯化步骤的区域选择性。使用 5 mol % Pd(OAc) 2在操作简单的条件下进行反应序列在六氟异丙醇中,并与各种亲核试剂相容,以提供结构不同的杂环骨架,包括吲哚、色烯、1,4-恶嗪、1,3-恶嗪、吡咯、异色酮和螺环己二酮。通过对药物和天然产物进行克级合成、指导基团去除和后期修饰,进一步证明了该方法的合成效用。对照研究表明,在活化的烯烃存在下,碳钯化对未活化的烯烃具有选择性。