Palladium-Catalyzed Asymmetric (2+3) Annulation of <i>p</i>-Quinone Methides with Trimethylenemethanes: Enantioselective Synthesis of Functionalized Chiral Spirocyclopentyl <i>p</i>-Dienones
作者:Zhi-Long Jia、Xian-Tao An、Yu-Hua Deng、Hui-Bin Wang、Kang-Ji Gan、Jing Zhang、Xian-He Zhao、Chun-An Fan
DOI:10.1021/acs.orglett.0c01252
日期:2020.6.5
A novel asymmetric catalytic (2+3) annulation of p-quinone methides with CN-substituted trimethylenemethane is described under palladium catalysis, providing an alternative approach for the enantioselective construction of highly functionalized chiral spirocyclopentyl p-dienones. Driven by the significant improvement in the reactivity and enantioselectivity, a novel type of non-C2-symmetric phosphoramidite
Formal (4+1) Cyclization of Ammonium Ylides with Vinylogous para-Quinone Methides
作者:Mario Waser、Lukas Roiser、Katharina Zielke
DOI:10.1055/s-0037-1610268
日期:2018.10
The formal (4+1) cyclization between in situ generated achiral carbonyl-stabilized ammonium ylides and vinylogous p-quinone methides can be carried out under operationally simple conditions, leading to two different double bond regioisomers depending on the conditions used. Apart from these racemic approaches, a first proof-of-concept for enantioselective versions of these reactions was also obtained
USE OF QUINONE METHIDES AS ANTIPOLYMERANTS FOR VINYLIC MONOMERS
申请人:Ecolab USA Inc.
公开号:US20160289147A1
公开(公告)日:2016-10-06
The present invention generally relates to compounds and methods for inhibiting the radical polymerization of unsaturated compounds, particularly vinyl monomers. More particularly, it relates to the use of cinnamyl quinone methides to inhibit the polymerization of unsaturated hydrocarbon compounds (e.g., vinyl monomers) soluble in organic solvents, particularly hydrocarbon streams.
Tandem Spirocyclopropanation/Rearrangement Reaction of Vinyl <i>p</i>-Quinone Methides with Sulfonium Salts: Synthesis of Spirocyclopentenyl <i>p</i>-Dienones
作者:Xiang-Zhi Zhang、Yu-Hua Deng、Kang-Ji Gan、Xu Yan、Ke-Yin Yu、Fang-Xin Wang、Chun-An Fan
DOI:10.1021/acs.orglett.7b00516
日期:2017.4.7
A novel base-mediated tandem spirocyclopropanation/rearrangement reaction of vinyl p-quinone methides (p-VQMs) with sulfonium salts is described. The unprecedented reactivity of p-VQMs was explored for the first time in the spiroannulation cascade, providing a stereoselective approach to the construction of synthetically interesting, densely functionalized spirocyclopentenyl p-dienones.
Synthesis of chromeno[4,3‐<scp><i>b</i></scp>]pyrrolidines from azomethine ylides and vinyl <scp><i>para</i></scp>‐quinone methides via (3 + 2) cycloaddition/oxa‐1,6‐addition
作者:Pei‐Shan Wu、Yan‐Cheng Liou、Gangababu Marri、Yi‐Ru Chen、Jia‐Rong Wu、Wenwei Lin
DOI:10.1002/jccs.202300328
日期:2023.12
efficient synthesis of chromeno[4,3-b]pyrrolidines has been successfully developed. This strategy involves a base-catalyzedreaction of p-VQMs and o-hydroxy azomethine ylides via (3 + 2) cycloaddition/oxa-1,6-addition reaction sequence. The reaction condition is mild, and a series of chromeno[4,3-b]pyrrolidines were obtained in 49-95% yields with excellent diastereoselectivity (dr > 20:1).
色烯[4,3- b ]吡咯烷的有效合成方法已成功开发。该策略涉及p -VQM 和邻羟基甲亚碱叶立德通过 (3 + 2) 环加成/oxa-1,6-加成反应序列进行碱催化反应。反应条件温和,得到了一系列色并[4,3- b ]吡咯烷,收率49-95%,具有优异的非对映选择性(dr > 20:1)。