The olefin isomerization/enantioselective intramolecular Alder-ene reaction cascade was achieved by using a cationic rhodium(I)/(R)-BINAP complex as a catalyst. A variety of substituted dihydrobenzofurans and dihydronaphthofurans were obtained from phenol- or naphthol-linked 1,7-enynes, respectively, with good yields and ee values.
Efficient microwave-assisted one-pot three-component synthesis of 2,3-disubstituted benzofurans under Sonogashira conditions
作者:Nataliya A. Markina、Yu Chen、Richard C. Larock
DOI:10.1016/j.tet.2013.02.003
日期:2013.4
efficient one-pot method for the synthesis of 2,3-disubstituted benzo[b]furans from commercially available 2-iodophenols, terminal acetylenes and aryl iodides has been developed utilizing Sonogashira reaction conditions. After an initial Sonogashira coupling of the 2-iodophenol with the terminal alkyne, cyclization involving the aryl iodide provides the 2,3-disubstituted benzo[b]furan in good to excellent
Indium(III)-Catalyzed Synthesis of Benzo[<i>b</i>]furans by Intramolecular Hydroalkoxylation of <i>ortho</i>-Alkynylphenols: Scope and Mechanistic Insights
作者:Lorena Alonso-Marañón、M. Montserrat Martínez、Luis A. Sarandeses、Enrique Gómez-Bengoa、José Pérez Sestelo
DOI:10.1021/acs.joc.8b00829
日期:2018.8.3
Indium(III) halides catalyze the hydroalkoxylation reaction of ortho-alkynylphenols to afford benzo[b]furans in good yields. The reaction proceeds with 5-endo-dig regioselectivity with a variety of phenols functionalized at the arene and alkyne moieties in high yields using InI3 (5 mol %) in DCE. Experimental and computational studies support a mechanism based on the indium(III) π-Lewis acid activation
卤化铟(III)催化邻炔基苯酚的加氢烷氧基化反应,以高收率提供苯并[ b ]呋喃。反应的进行与5-内切-挖区域选择性与各种在芳烃官能酚类和以高产率使用的InI炔基部分3在DCE(5摩尔%)。实验和计算研究支持了基于炔烃的铟(III)π-路易斯酸活化,然后进行苯酚的亲核加成和最终的原金属脱金属,得到相应的苯并[ b ]呋喃的机理。DFT计算表明二聚体In 2 I 6 是通过与炔烃和羟基的新型双配位而催化的物质。
Gold-Catalyzed Enynal and Enynol Coupling by Selectively Steering Two Transient Vinyl-Gold Intermediates
作者:Zipeng Wang、Tongxiang Cao、Shifa Zhu
DOI:10.1021/acs.orglett.2c03890
日期:2022.12.23
bond is easily accessible but less exploited in homogeneous gold catalysis, which possesses weak nucleophilicity and would be likely to undergo protodemetalation. Herein, a gold-catalyzed enynal and enynol coupling by selectively steering two transient vinyl-gold intermediates is realized under mild conditions. It exhibits high atom economy and good tolerance of functional groups with the added benefit
A copper-catalyzed annulative amination approach to 3-aminobenzofurans and -indoles from o-alkynylphenols and -anilines has been developed. The Cu-based catalysis is based on an umpolung, electrophilic amination with O-benzoyl hydroxylamines and enables the mild and convergent synthesis of various 3-aminobenzoheteroles of biological and pharmaceutical interest. Some mechanistic investigations and an application of this protocol to construction of more complex tricyclic framework are also described.
Copper-Mediated Annulative Direct Coupling of <i>o</i>-Alkynylphenols with Oxadiazoles: A Dehydrogenative Cascade Construction of Biheteroaryls
A copper-mediated annulative direct coupling of o-alkynylphenols with 1,3,4-oxadiazoles proceeds smoothly even under ambient conditions to afford the corresponding biheteroaryls. The reaction system represents a new avenue for the construction of biheteroaryl molecules of interest in their biological and physical properties.