在此,报道了N-芳酰基吲哚和( E )-β-氯乙烯基酮之间的钯催化的非对映选择性脱芳构化/交叉偶联环化反应。通过这种环化/环异构化级联,获得了一系列含呋喃二氢吲哚,产率高达 95%。该反应具有易于获得的起始原料、苄基Pd(II)催化的( E )-β-氯乙烯基酮环异构化、三键和双杂环的顺序形成以及优异的非对映选择性。更重要的是,卡宾-仲苄基迁移插入被证明是顺序环化中的关键过程。
A One-Pot Synthesis of Pyranone and Pyrrole Derivatives from β-Chlorovinyl Ketones via Direct Conjugate Addition Approach
作者:Hun Young Kim、Kyungsoo Oh
DOI:10.1021/acs.orglett.7b02381
日期:2017.9.15
The direct conjugate addition reactions of imino esters to β-chlorovinyl ketones have been accomplished in the presence of a substoichiometric amount of hard base, LiHMDS. An in situ generated species from the conjugate addition reaction readily acted as autocatalyst to convert the imino esters to its corresponding enolates. By utilizing a sequence of conjugate addition/elimination/lactonization followed
Studies on Elimination Pathways of β-Halovinyl Ketones Leading to Allenyl and Propargyl Ketones and Furans under the Action of Mild Bases
作者:Hun Young Kim、Jian-Yuan Li、Kyungsoo Oh
DOI:10.1021/jo302253c
日期:2012.12.21
stereochemically defined β-halovinyl ketones has been investigated using a mild base, NEt3, leading to the formation of allenyl ketones and propargyl ketones. A preferential α-vinyl enolization of (E)-β-chlorovinyl ketones has been observed where a nonplanar s-cis conformation is proposed as a dominant conformation as opposed to a planar s-cis conformation of (Z)-β-chlorovinyl ketones. Other eliminative pathways
1,3-Dienones and 2<i>H</i>-Pyran-2-ones from Soft α-Vinyl Enolization of β-Chlorovinyl Ketones: Defined Roles of Brönsted and Lewis Base
作者:Hun Young Kim、Kyungsoo Oh
DOI:10.1021/acs.orglett.5b03265
日期:2015.12.18
The eliminative reaction pathways of (E)-β-chlorovinyl ketones were investigated in the presence of both Brönsted and Lewis bases. The Brönsted base, Et3N, effected the soft α-vinyl enolization of (E)-β-chlorovinyl ketones to [3]cumulenol intermediates; in turn, a catalytic amount of Lewis base, PPh3, initiated isomerization to provide 1,3-dienones in high yields. The introduction of a carbon-based
在布朗斯台德碱和路易斯碱的存在下研究了(E)-β-氯乙烯基酮的消除反应途径。布朗斯台德碱Et 3 N影响了(E)-β-氯乙烯基酮向[3]异丙苯三酚中间体的软α-乙烯基烯醇化作用。进而,催化量的路易斯碱PPh 3引发了异构化反应,以高收率提供了1,3-二烯酮。将碳基亲核试剂引入反应混合物中,可在一锅中高效合成2 H -pyran-2-one,其中碳基亲核试剂是由额外等价的布朗斯台德碱Et 3生成的N,攻击亲电的[3]枯烯酚中间体以起始环化,得到2 H-吡喃-2-酮。
A facile synthesis of 3,4-dimercaptofurans via sulfenylation of (E)-β-chlorovinyl ketones and 1,2-sulfur migration
作者:E. Song、H. Y. Kim、K. Oh
DOI:10.1039/c6ob02772e
日期:——
The one-pot sulfenylation of (E)-β-chlorovinyl ketones was investigated under soft α-vinyl enolization conditions. Modulating the nature of nucleophilic species using a “hard” base the regioselective formation of α,γ-dithio-allenyl ketones has been achieved, where the thermodynamic control was mimicked by the presence of Et3N·HCl. The sulfenylated products, α,γ-dithio-allenyl and α,α-dithio-propargyl
One-Pot Synthesis of <i>N</i>-Hydroxypyrroles via Soft α-Vinyl Enolization of (<i>E</i>)-β-Chlorovinyl Ketones: A Traceless Arylsulfinate Mediator Strategy
作者:Divya Bhatt、Soyeon Chae、Hun Young Kim、Kyungsoo Oh
DOI:10.1021/acs.orglett.2c00649
日期:2022.4.15
reaction course of β-chlorovinyl ketones with N-hydroxyamine. The soft α-vinyl enolization of (E)-β-chlorovinyl ketones was conducted in the presence of sodium arylsulfinate to give transient alkenyl sulfones that in turn reacted with NH2OH to give novel access to N-hydroxypyrroles. The mechanistic studies revealed the initial formation of oxazine intermediates that rearranged to thermodynamically stable
已经开发了一种无痕芳基亚磺酸盐介质策略来改变 β-氯乙烯基酮与N-羟胺的反应过程。( E )-β-氯乙烯基酮的软 α-乙烯基烯醇化在芳基亚磺酸钠存在下进行,得到瞬态烯基砜,后者又与 NH 2 OH 反应,得到N-羟基吡咯的新途径。机理研究揭示了在微波辅助加热条件下重排成热力学稳定的芳烃产物N-羟基吡咯的恶嗪中间体的初始形成。