Highly Efficient Synthesis of Allenes from Trimethylaluminum Reagent and Propargyl Acetates Mediated by a Palladium Catalyst
作者:Qing-Han Li、Jung-Yuan Jeng、Han-Mou Gau
DOI:10.1002/ejoc.201403008
日期:2014.12
A series of propargylacetates were prepared and used as propargyl electrophiles for coupling reactions with trimethylaluminum. The simple catalytic system of palladium(II) acetate (1 mol-%) and tri(o-tolyl)phosphine (2 mol-%) worked efficiently for a wide variety of aromatic and aliphatic propargylacetates, producing the substituted allenes in good to excellent yields of up to 94 % in tetrahydrofuran
制备了一系列乙酸炔丙酯并将其用作炔丙基亲电试剂与三甲基铝进行偶联反应。乙酸钯 (II) (1 mol-%) 和三(邻甲苯基)膦(2 mol-%)的简单催化体系对多种芳香族和脂肪族乙酸炔丙酯有效地工作,产生了良好的取代丙二烯在四氢呋喃中的产率高达 94%。该过程简单易行,为合成取代的丙二烯衍生物提供了一种有效的方法。根据实验结果,提出了一种可能的催化循环。
Synthesis of multi-substituted allenes from organoalane reagents and propargyl esters by using a nickel catalyst
作者:Xue Bei Shao、Zhen Zhang、Qing Han Li、Zhi Gang Zhao
DOI:10.1039/c8ob00781k
日期:——
A highly efficient and simple route for the synthesis of multi-substituted allenes has been developed by a nickel catalyzed SN2′ substitution reaction of propargyl esters with organic aluminium reagents under mild conditions, which gave the corresponding multi-substituted allenes in good to excellent yields (up to 92%) and high selectivities (up to 99%) at 60 °C for 6 h in THF. Aryls bearing electron-donating
在温和的条件下,通过炔丙基酯与有机铝试剂的镍催化的S N 2'取代反应,开发了一种高效且简单的合成多取代的烯的方法,得到了相应的优等的多取代的烯。在THF中在60°C下反应6小时可得到高产率(最高92%)和高选择性(最高99%)。炔丙基酯中带有给电子或吸电子基团的芳基收率高。另外,带有噻吩基或吡啶基的多取代的亚丙基以95-97%的选择性获得,分离产率为72-83%。此外,S N2'取代反应也与炔丙基碳酸酯化合物有效地起作用。根据实验结果,提出了可能的催化循环。
Diastereoselective Synthesis of <i>C</i>-Vinyl Glycosides via Gold(I)-Catalyzed Tandem 1,3-Acyloxy Migration/Ferrier Rearrangement
作者:Nianyu Huang、Hongze Liao、Hui Yao、Tianpeng Xie、Shasha Zhang、Kun Zou、Xue-Wei Liu
DOI:10.1021/acs.orglett.7b03062
日期:2018.1.5
A novel gold-catalyzed C-glycosylation has been developed to gain access to α,(Z)-selective C-vinyl glycosides, starting from readily available glycals and propargylic carboxylate. This reaction involves a tandem intermolecular gold-catalyzed 1,3-acyloxy migration/Ferrier rearrangement with the involvement of allenic ester as the glycosyl acceptor. A wide range of substrate scope with good to excellent
Sequential Carbon–Carbon/Carbon–Selenium Bond Formation Mediated by Iron(III) Chloride and Diorganyl Diselenides: Synthesis and Reactivity of 2-Organoselenyl-Naphthalenes
作者:Ana M. S. Recchi、Davi F. Back、Gilson Zeni
DOI:10.1021/acs.joc.7b00050
日期:2017.3.3
we report an intramolecular cyclization of benzylic-substituted propargyl alcohols promoted by iron(III) chloride and diorganyl diselenides to give 2-organoselenyl-naphthalenes via a sequential carbon–carbon/carbon–selenium bondformation. The present reaction tolerated a wide range of substituents in both propargyl alcohols and diorganyl diselenides to give the desired 2-organoselenyl-naphthalenes