亚磺酸的不同加成模式被开发用于烯酮的化学发散磺酰化,其中烯酮的炔部分的离子磺酰化是通过盐控制的顺式加成途径实现的。烯烃部分的自由基磺酰化也提供了立体定义的磺酰化烯烃。还探索了Ti(O i -Pr) 4催化的 ( E )-β-氯乙烯基酮的 α-乙烯基醛醇缩合,然后进行化学发散磺酰化的一锅串联序列,从而可以轻松获得高度取代的二烯和埃尼斯。
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。
Ambivalent Reactivity Modes of β-Chlorovinyl Ketones: Electrophilic Lithium [3]Cumulenolates from Soft Vinyl Enolization Strategy
作者:Hun Young Kim、Edward Oscar Rooney、Raymond Phillip Meury、Kyungsoo Oh
DOI:10.1002/anie.201302750
日期:2013.7.29
Soft spot: The softvinylenolization of (E)‐β‐chlorovinyl ketones results in the in situ generation of electrophiliclithium [3]cumulenolates, which react with nucleophiles such as another lithium [3]cumulenolate to stereoselectively form vinyl allenones. They can also react with ketimine esters to give 3‐methylenepyrrolidines.
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。
Cu(OTf)
<sub>2</sub>
‐Catalyzed Aerobic Cycloisomerization of Alkenyl Sulfones to Furans Using (
<i>E</i>
)‐β‐Chlorovinyl Ketones and Sodium Sulfinates
作者:Divya Bhatt、Hun Young Kim、Kyungsoo Oh
DOI:10.1002/adsc.202200776
日期:2022.10.18
the aerobic cycloisomerization of alkenyl sulfone intermediates has been established for the synthesis of 3-sulfonyl furans. The optimal cycloisomerization catalyst system was identified to be Cu(OTf)2, where molecular oxygen acts as a terminal oxidant. With three points of structural variation in both β-chlorovinyl ketones and sodium sulfinates, the current aerobic cycloisomerization strategy allows
亚磺酸钠与 ( E )-β-氯乙烯基酮的加成,然后是烯基砜中间体的需氧环化异构化,已被证实可用于合成 3-磺酰基呋喃。最佳环异构化催化剂体系被确定为 Cu(OTf) 2,其中分子氧充当末端氧化剂。由于 β-氯乙烯酮和亚磺酸钠的三点结构变化,目前的好氧环异构化策略允许合成高度官能化和取代的呋喃衍生物。