1,3-Dialkynyl- and 1,3-Dialkenylisobenzofurans: New π-Extended Congeners Prepared by Double Nucleophilic Addition of Alkynyllithiums to <i>o</i>-Phthalaldehyde
作者:Ryoji Kudo、Kei Kitamura、Toshiyuki Hamura
DOI:10.1246/cl.160884
日期:2017.1.5
Efficient synthetic route to 1,3-dialkynyl- and 1,3-dialkenylisobenzofurans, new π-extended congeners of isobenzofurans, was reported. A three-step protocol including doublenucleophilicadditions of alkynyllithiums to o-phthalaldehyde and selective oxidation enables us to prepare various functionalized π-extended isobenzofurans. The photophysical properties of these π-extended isobenzofurans are also
Highly Efficient Brønsted Acid-Catalyzed Cycloisomerizations of Alkynes Bearing Bis(acetoxy) Groups to Indenyl Ketones
作者:Yuanhong Liu、Shaolin Zhou、Guijie Li、Bin Yan、Shenghai Guo、Yebing Zhou、Hao Zhang、Peng George Wang
DOI:10.1002/adsc.200800037
日期:2008.4.7
A Brønstedacid-catalyzedcycloisomerization of functionalized alkynes is described, which is assumed to be initiated through the formation of a benzylic cation intermediate. The reaction offers a highlyefficient and straightforward route to indenylketones with a wide range of substituents under mild conditions.
Recursive Anion-Triggered Tandem Reactions of <i>ortho</i>-Bis-ynones: Tunable Synthesis of 1-Indenones and Cyclopenta[<i>a</i>]inden-8(2<i>H</i>)-ones
Recursive anion-mediated activation of o-bis-ynones sets off a Michael addition–aldol reaction–dehydrative rearrangement cascade, leading to the one-potsynthesis of 1-indenones via orthogonal interplay between the two ortho-ynone moieties. Repeating the recursive anion engagement with the 1-indenones unfolded access to a functionally embellished cyclopenta[a]inden-8(2H)-one core and its spiroannulated
递归阴离子介导的邻-双-炔酮活化引发迈克尔加成-醛醇反应-脱水重排级联反应,通过两个邻-炔酮部分之间的正交相互作用导致一锅法合成1-茚酮。重复与 1-茚酮的递归阴离子结合,展开获得功能修饰的 cyclopenta[ a ]inden-8(2 H )-one 核心及其螺环化类似物,直接或逐步通过串联 1,6-Michael 型加成–6π电环化和原位氧化序列。
PBr<sub>3</sub>-Mediated Cyclization of 1,7-Diyn-3,6-bis(propargyl carbonate)s: Synthesis of 5-Bromotetracenes
作者:Ning Sun、Haoyi Chen、Xiangdong Li、Murong Xu、Yi Gan、Liangwei Zhang、Yuanhong Liu
DOI:10.1021/acs.joc.7b01519
日期:2017.10.6
A new and straightforward method for the synthesis of 5-bromotetracenes through PBr3-mediated cyclization of 1,7-diyn-3,6-bis(propargyl carbonate)s has been developed. This method offers several advantages such as easily accessible starting materials, high efficiency, and wide functional group compatibility. In addition, chloro- and iodo-substituted tetracenes were also synthesized using appropriate halogenating reagents. The utility of the 5-bromotetracene products has been illustrated by their efficient transformations through various palladium-catalyzed cross-coupling reactions.