Synthesis of 3‐Organoselenyl‐2
<i>H</i>
‐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.
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。
Assembly of 3-(trifluoromethyl)thiochromenes via a regioselective trifluoromethylthioarylation of (3-arylprop-2-ynyl)oxybenzenes with trifluoromethanesulfanylamide
作者:Tong Liu、Guanyinsheng Qiu、Qiuping Ding、Jie Wu
DOI:10.1016/j.tet.2016.01.053
日期:2016.3
trifluoromethanesulfanylamide is reported, which affords 3-(trifluoromethyl)thiochromenes in good yields with high regioselectivity. The reaction works efficiently in the presence of 2.0 equiv of bismuth chloride, and different functional groups can be compatible under the conditions. The related (3,4-dihydronaphthalen-2-yl) (trifluoromethyl)sulfane and 3-((trifluoromethyl)thio)-1,2-dihydroquinoline can be generated
efficient protocol for the synthesis of thioesters-functionalized 2-benzopyrans has been developed through a palladium-catalyzed one-pot cyclization/thiocarbonylation reaction of propargyl ethers with sulfonylchlorides as promising and easily accessible sulfur sources. The reaction showed good compatibility towards versatile functional groups, both aryl and alkylsulfonyl chlorides were well tolerated. Without
the generality of gold versus silver catalyzed intramolecular hydroarylation reactions of 3-[(3-arylprop-2-ynyl)oxy]benzenederivatives in terms of rings substitution were investigated. Only products deriving from 6-endo cyclization were exclusively formed. The features of substituents had a considerable effect on the reaction outcome in the presence of silver catalysis, whereas gold catalysis revealed