Gold-Catalyzed Synthesis of Benzil Derivatives and α-Keto Imides via Oxidation of Alkynes
摘要:
An efficient process based on the gold-catalyzed redox reaction has been developed to oxidize 1,2-diarylacetylene or ynamide to 1,2diaryldiketone or a-keto imide respectively. This process can tolerate a variety of functional groups and affords 1,2-dicarbonyl compounds in excellent yields under mild reaction conditions.
two‐step strategy for thiopeptide bond formation with readily available monothiocarboxylic acids as thioacyl donors is described. The α‐thioacyloxyenamide intermediates formed from the ynamides and monothiocarboxylic acids can be purified, characterized, and stored. The balance between their activity and stability enables them to act as effective thioacylating reagents to afford thiopeptide bonds under mild
An efficient intermolecular trans-selective β-hydroamidation of ynamides to furnish a series of (Z)-ethene-1,2-diamide derivatives with excellent regio- and stereo-selectivities is described. The trans-β-addition reactions have been illustrated for a wide range of substrates and proceeded under basic reaction conditions using readily available materials in the absence of a transition-metal catalyst
Borane-Catalyzed Selective Hydrosilylation of Internal Ynamides Leading to β-Silyl (<i>Z</i>)-Enamides
作者:Youngchan Kim、Ramesh B. Dateer、Sukbok Chang
DOI:10.1021/acs.orglett.6b03485
日期:2017.1.6
We have developed a borane-catalyzed regio- and stereoselectivehydrosilylation of internal ynamides for the first time. The scope of ynamide substrates and silane reactants was broad undermild reaction conditions, affording synthetically versatile β-silyl (Z)-enamide products. The observed stereoselectivity was reasoned to be due to the β-silicon effect on a postulated ketene iminium intermediate
Decarbonylative Coupling of α-Keto Acids and Ynamides for Synthesis of β-Keto Imides
作者:Renjie Chen、Linwei Zeng、Bo Huang、Yangyong Shen、Sunliang Cui
DOI:10.1021/acs.orglett.8b01302
日期:2018.6.1
A novel decarbonylative coupling of α-keto acids and ynamides with extrusion of CO for synthesis of β-keto imides is reported. This process features mild reaction conditions, a broad substrate scope, and high efficiency. An isotope-labeling reaction and GC analysis were conducted to elucidate a plausible reaction mechanism.
In this study, a concise and atom-economical TfOH-mediated [2 + 2 + 2] cycloaddition of ynamides with two discrete nitriles is developed to synthesize multi-substituted 4-aminopyrimidine. A variety of functional groups and sterically and electronically diverse reaction partners are tolerated. The products were obtained in good to excellent yields.