Synthesis of 1,4-Enamino Ketones by [3,3]-Rearrangements of Dialkenylhydroxylamines
作者:Wiktoria H. Pecak、Jongwoo Son、Amy J. Burnstine、Laura L. Anderson
DOI:10.1021/ol501230e
日期:2014.7.3
4-enamino ketones has been achieved through the [3,3]-rearrangement of dialkenylhydroxylamines generated from the addition of N-alkenylnitrones to electron-deficient allenes. The mild conditions required for this reaction, and the simultaneous installation of a fluorenyl imine N-protecting group as a consequence of the rearrangement, avoid spontaneous cyclization of the 1,4-enamino ketones to form the
Synthesis of Pyrazoles Based on Functionalized Allenoates
作者:Ilshat M. Sakhautdinov、Aynur M. Gumerov、Ilnur R. Batyrshin、Akhnaf A. Fatykhov、Kyrill Yu. Suponitsky、Marat S. Yunusov
DOI:10.3987/com-13-12910
日期:——
Regiospecific synthesis of pyrazole-3-carboxylate derivatives by 1,3-dipolar cycloaddition of diazomethane with allenoates in presence of triethylamine is demonstrated. Reaction of allenoates with stearic acid moiety containing diazoketone is explored under ultrasonic conditions. Novel derivatives of pyrazole were achieved in excellent yields. INTRODUCTION Among compounds containing nitrogen heterocyclic frameworks
One-Step Asymmetric Construction of 1,4-Stereocenters via Tandem Mannich-Isomerization Reactions Mediated by a Dual-Functional Betaine Catalyst
作者:Yu Deng、Xiaohuo Shi、Guangfa Shi、Xingyu Lu、Jisheng Luo、Li Deng
DOI:10.1021/jacsau.2c00465
日期:2022.12.26
Mannich-isomerization reaction that allows the direct construction of 1,4-stereocenters in a highly stereoselective manner. This asymmetric transformation demonstrated the potential of a tandem nucleophilic addition-isomerization reaction as a broadly useful strategy for the efficient construction of 1,4-stereocenters. Notably, this tandem reaction was mediated by a single chiral betaine as a dual-functional
Asymmetric Olefin Isomerization of Butenolides via Proton Transfer Catalysis by an Organic Molecule
作者:Yongwei Wu、Ravi P. Singh、Li Deng
DOI:10.1021/ja205674x
日期:2011.8.17
general olefin isomerization was realized via biomimetic protontransfer catalysis with a new chiral organic catalyst. A broad range of mono- and disubstituted β,γ-unsaturated butenolides were transformed into the corresponding chiral α,β-unsaturated butenolides in high enantioselectivity and yield in the presence of as low as 0.5 mol % catalyst. Mechanistic studies have revealed the protonation as the