Electrochemical Selective Oxidative Synthesis of Diversified Sulfur Heterocycles from
<scp>β‐Ketothioamides</scp>
作者:Li‐Rong Wen、Ning‐Ning Wang、Wu‐Bo Du、Ming‐Zhe Zhu、Chao Pan、Lin‐Bao Zhang、Ming Li
DOI:10.1002/cjoc.202100132
日期:2021.7
diversified sulfurheterocycles has been described through organic electrosynthesis means. In undivided cell, dihydrothiophenes, thiazolines and 1,4-dithiines could be easily generated from various available β-ketothioamides under metal-free and external oxidant-free conditions. The transformation underwent smoothly under mild conditions and could be easily scaled-up. Moreover, different sulfur heterocycles
Synthesis of pyrrole disulfides <i>via</i> umpolung of β-ketothioamides
作者:Xiangrui Meng、Weisi Guo、Guangming Nan、Ming Li
DOI:10.1039/d2ob01506d
日期:——
Na2CO3-promoted reaction of β-ketothioamides (KTAs) and cyanoacetates was developed for the synthesis of pyrrole disulfides using air as a green oxidant. This protocol features a broad substrate scope and mild reaction conditions. Preliminary mechanistic studies indicate that the reaction involves a tandem unusual umpolung of KTAs, N-cyclization, tautomerization and oxidative coupling process.
使用空气作为绿色氧化剂,开发了一种 Na 2 CO 3促进的 β-酮硫代酰胺 (KTA) 和氰基乙酸盐的反应,用于合成吡咯二硫化物。该协议具有广泛的底物范围和温和的反应条件。初步的机理研究表明,该反应涉及 KTA 的串联不寻常 umpolung、N-环化、互变异构和氧化偶联过程。
TBHP‐Mediated Intermolecular Radical Coupling and Intramolecular Cyclization Cascade: Access to Furo[2,3‐<i>b</i>]quinoxalines and Their Photophysical Study
accessible β-ketothioamides and quinoxalin-2-ones in open flask at room temperature under TBHP mediated conditions. Mechanistic studies revealed that the overall reactivity relies on the seamless integration of intermolecular radical coupling and intramolecularcyclization via desulfhydration of C=S bond cleavage. Generation of H2S as the only by-product makes this process highly attractive. Furthermore
我们设计了一种级联一锅法策略,在室温下、TBHP 介导的条件下,在敞口烧瓶中,用易于获得的 β-酮硫酰胺和喹喔啉-2-酮构建 31 个呋喃稠合喹喔啉实例,产率高达 88%。机理研究表明,整体反应性依赖于分子间自由基偶联和通过C=S键断裂脱硫的分子内环化的无缝整合。 H 2 S的生成作为唯一的副产品使得该过程极具吸引力。此外,还研究了呋喃稠合喹喔啉的光物理行为。
Yb(OTf)<sub>3</sub>-Mediated Access to Furans from β-Ketothioamides via Eschenmoser Sulfide Contraction Reaction
作者:Ming Li、Xiang-Jing Kong、Li-Rong Wen
DOI:10.1021/acs.joc.5b01924
日期:2015.12.18
A mild and straightforward synthetic protocol for construction of a Loran skeleton promoted by Yb(OTf)(3) from beta-ketothioamides and arylglyoxals has been developed at room temperature. Importantly, this protocol involves a tandem sequence that includes aldol condensation, N-cyclization, ring opening, O-cyclization, S-cyclization, and Eschenmoser sulfide contraction.
Reactivity of Functionalized <i>N</i>,<i>S</i>-Ketene Acetal: Regioselective Construction of Tetrahydrobenzo[<i>b</i>]pyran and Chromeno[2,3-<i>b</i>]quinoline Derivatives
作者:Ming Li、Yan-Li Hou、Li-Rong Wen、Fu-Meng Gong
DOI:10.1021/jo101902z
日期:2010.12.17
Regioselective synthesis of functionalized tetrahydrobenzo[b]pyrans has been developed by multi-component reactions (MCRs) and tandem [3 + 3] annulations of beta-benzoylthioacetanilides or beta-(2-haloaroyl)thioacetanilides as valuable sources with aromatic aldehydes and 5,5-dimethy1-1,3-cyclohexanedione catalyzed by triethylamine. This MCR followed by a postcondensation cyclization via an intramolecular SNAr in the presence of K2CO3 led to an unprecedented novel chromeno-[2,3-b]quinoline framework containing an important chromene moiety in good yields. The reactions were very mild, convenient, and o-selective to form new fused tetracyclic target molecules.