Room Temperature Copper(II)-Catalyzed Oxidative Cyclization of Enamides to 2,5-Disubstituted Oxazoles via Vinylic C–H Functionalization
摘要:
A copper(11)-catalyzed oxidative cyclization of enamides to oxazoles via vinylic C-H bond functionalization at room temperature is described. Various 2,5-disubstituted oxazoles bearing aryl, vinyl, alkyl, and heteroaryl substituents could be synthesized in moderate to high yields. This reaction protocol is complementary to our previously reported iodine-mediated cyclization of enamides to afford 2,4,5-trisubstituted oxazoles.
Stereoselective Synthesis of Enamides by a Peterson Reaction Manifold
摘要:
[GRAPHICS]Vinylsilanes are converted into enamides by a sequence comprising epoxidation, nucleophilic ring opening of the resulting epoxysilanes with NaN3, and reduction of the azide, followed by a "one-pot" N-acylation/Peterson elimination process. This method is distinguished by its wide applicability and stereoselective course.
Decarboxylative Enamide Synthesis from Carboxylic Acid and Alkenyl Isocyanate
作者:Rui Wang、Wenbo H. Liu
DOI:10.1021/acs.orglett.3c01682
日期:2023.7.21
protocol to access the enamide via employing carboxylic acid and alkenyl isocyanate as the precursors promoted by DMAP without involving any metal catalysts and dehydration reagents. This protocol is simple and practical and tolerates numerous functional groups. Considering the simplicity, the ready availability of both starting materials, and the significance of the enamides, we expect that this reaction
Herein, a selective and efficient CO2-mediated Z to E isomerization of enamides is reported. Notably, CO2 acts as a promoter to form the key reaction intermediate. This protocol provides a novel method for the selective isomerization of enamides under mild conditions with moderate to excellent yields. The method exhibits a broad substrate scope, including late-stage modification of biorelevant molecules
在此,报道了烯酰胺的选择性且有效的CO 2介导的Z至E异构化。值得注意的是,CO 2充当形成关键反应中间体的促进剂。该方案提供了一种在温和条件下选择性异构化烯酰胺的新方法,具有中等至优异的产率。该方法具有广泛的底物范围,包括生物相关分子的后期修饰。通过循环伏安法 (CV) 和密度泛函理论 (DFT) 计算得出的机理见解提供了证据,证明中间体通过非常规的 C 中心模式促进了反应。