Synthesis of dibenzocyclohepta[1,2-<i>a</i>]naphthalene derivatives from phenylacetaldehyde and alkynyl benzyl alcohols <i>via</i> sequential electrophilic addition and double Friedel–Crafts reactions
作者:Archana K. Sahu、Ramanjaneyulu Unnava、Bipin K. Behera、Anil K. Saikia
DOI:10.1039/d1ob00057h
日期:——
been developed for the synthesis of substituted 9H-dibenzo[3,4:6,7]-cyclohepta[1,2-a]naphthalenes from phenylacetaldehydes and ortho-alkynyl benzyl alcohols in the presence of a Lewis acid in moderate to good yields within a short reaction time. Interestingly, the reaction proceeds through a highly regioselective electrophilic addition followed by double Friedel–Crafts reaction to form uncommon dibenzo-fused
已经开发了一种简单的方法,用于在路易斯酸存在下,由苯乙醛和邻炔基苄基醇合成取代的9 H-二苯并[3,4:6,7]-环庚[1,2- a ]萘。在较短的反应时间内中度到良好的收率。有趣的是,该反应是通过高度区域选择性的亲电加成反应进行的,然后进行两次Friedel-Crafts反应,形成不常见的二苯并稠合的七元碳环。
Construction of Six-Membered Silacyclic Skeletons via Platinum-Catalyzed Tandem Hydrosilylation/Cyclization with Dihydrosilanes
Catalytic silicon‐carbon or silicon‐heteroatom bond‐forming hydrosilylation has become increasingly important in synthetic chemistry, catalysis and organosilicon chemistry. Herein we report a platinum‐catalyzed one‐pot and tandem hydrosilylation/cyclization of OH‐containing alkynes with dihydrosilanes, allowing for facile synthesis of six‐membered organosiliconcompounds, including silyloxycycles and
Synthesis of 2-Aryl Acetophenones via Hydrobromination and Oxy-isomerization of (<i>o</i>-Arylethynyl)benzyl Alcohols
作者:Tzu-Hsuan Kuan、Duen-Ren Hou
DOI:10.1021/acs.joc.1c00294
日期:2021.5.7
Hydrobromination and oxy-isomerization of (o-arylethynyl)benzyl alcohols to yield brominated aryl ketones were achieved with bromotrimethylsilane. The substrate scope suggested that vinyl carbocations, stabilized by the conjugated aryl groups, are the reaction intermediates. 1H-Isochromene was also detected by 1H NMR, and an isolated 1H-isochromene was converted to the product when retreated with TMSBr
用溴代三甲基硅烷实现了(邻-芳基乙炔基)苄醇的氢溴化和氧异构化,生成溴化的芳基酮。底物范围表明,通过共轭芳基稳定的乙烯基碳阳离子是反应中间体。还通过1 H NMR检测到1 H-异戊二烯,当用TMSBr处理时,分离出的1 H-异戊二烯转化为产物。1 H-异戊二烯的形成等同于6-内挖-环化,并与在基本条件下的相应反应形成对比,在该条件下,以5-外-挖为主导。
Selective cyclization of alkynols and alkynylamines catalyzed by potassium tert-butoxide
作者:Deng Yuan Li、Ke Ji Shi、Xiao Feng Mao、Zheng Le Zhao、Xin Yan Wu、Pei Nian Liu
DOI:10.1016/j.tet.2014.06.078
日期:2014.9
Transition Metal-Free Cascade Reactions of Alkynols to Afford Isoquinolin-1(2<i>H</i>)-one and Dihydroisobenzofuran Derivatives
作者:Deng Yuan Li、Ke Ji Shi、Xiao Feng Mao、Guo Rong Chen、Pei Nian Liu
DOI:10.1021/jo5006312
日期:2014.5.16
Transition metal-free cascade reactions of alkynols with imines have been achieved using potassium tert-butoxide as catalyst. Switching the reaction solvent gives two kinds of products in good yield: isoquinolin-1(2H)-one derivatives and dihydroisobenzofuran derivatives. This approach was used to generate the natural product 8-oxypseudopalmatine in a two-step procedure from commercially available starting materials. Additionally, multicomponent reactions of alkynols, aldehydes, and amines were also successfully achieved to afford isoquinolin-1(2H)-one derivatives.