Iron-Catalyzed Amidation of Alkynyl Bromides: A Facile Route for the Preparation of Ynamides
摘要:
A facile route to obtain ynamides in high yields was described. The products were achieved through the iron-catalyzed C-N coupling reaction of amides with alkynyl bromides in the presence of 20 mol % of N,N'-dimethylethane-1,2-diamine (DMEDA).
Selenium-π-Acid Catalyzed Oxidative Functionalization of Alkynes: Facile Access to Ynones and Multisubstituted Oxazoles
作者:Lihao Liao、Hang Zhang、Xiaodan Zhao
DOI:10.1021/acscatal.8b01595
日期:2018.7.6
Unprecedented selenium-catalyzed propargylic oxidation of alkynes is disclosed. Various propargylphosphonates and 3-alkynoates were efficiently converted to valuable ynones via unusual C–C triple bond migration and deselenenylation at a vinyl carbon. By the strategies of tautomerization of enamine intermediate and SN2 displacement, similar conditions were effective for the oxidative difunctionalization
公开了前所未有的硒催化炔烃的炔丙基氧化。各种炔丙基膦酸酯和3-链烷酸酯通过不寻常的CC三键迁移和乙烯基碳上的硒烯基化反应,有效地转化为有价值的炔酮。通过烯胺中间体的互变异构和S N 2置换的策略,相似的条件对于乙酰胺的氧化双官能化有效,从而提供了具有高区域选择性的多取代恶唑。机理研究揭示了这些详细的过程。
Stereoselective Synthesis of (2<i>Z</i>)-2,4-Dienamides via NBS-Mediated Allyloxyl Addition–Claisen Rearrangement–Dehydrobromination Cascade Reaction of Ynsulfonamides
An NBS-promoted allyloxyl addition-Claisen reatrangement-dehydrobtomination cascade reaction has been developed. More than 20 substituted alkynylsulfonamides were reacted with allyl alcohols to generate (2Z)-2,4-dienamides in moderate to high yields. A mechanistic model has been proposed to account for the overall reaction sequence including the stereochemical outcome. Theoretical calculations suggested that a [3,3] sigmatropic rearrangement be the rate-limiting step.
Iron-Catalyzed Amidation of Alkynyl Bromides: A Facile Route for the Preparation of Ynamides
A facile route to obtain ynamides in high yields was described. The products were achieved through the iron-catalyzed C-N coupling reaction of amides with alkynyl bromides in the presence of 20 mol % of N,N'-dimethylethane-1,2-diamine (DMEDA).
The Carbocation-Catalyzed Intermolecular Formal [2 + 2 + 1] Cycloaddition of Ynamides with Quinoxaline <i>N</i>-Oxides
作者:Hongming Jin、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1021/acscatal.9b03911
日期:2019.12.6
Carbocation-catalyzed oxidative [2 + 2 + 1] annulation of two molecules of ynamide with 2,3-dichloroquinoxaline N-oxide enables the facile and convergent assembly of fully substituted symmetric and unsymmetric furan frameworks. The quinoxaline N-oxide presented a remarkable discrepancy to common quinoline and pyridine N-oxides. A wide range of functional groups is well compatible due to the mild conditions