An efficient and regioselective cobalt-catalyzed synthesis of multi-substituted pyrroles is reported by the use of readily available enamides and alkynes. The success of the process relies on the employment of a catalytic amount of Cp*Co(CO)I2 together with CuO as the oxidant.
Palladium-Catalyzed Dual Ligand-Enabled Alkylation of Silyl Enol Ether and Enamide under Irradiation: Scope, Mechanism, and Theoretical Elucidation of Hybrid Alkyl Pd(I)-Radical Species
作者:Bin Zhao、Rui Shang、Guang-Zu Wang、Shaohong Wang、Hui Chen、Yao Fu
DOI:10.1021/acscatal.9b04699
日期:2020.1.17
dual ligand effect and the irradiation effect in the catalytic cycle. The reaction is suggested to proceed via a hybrid alkyl Pd(I)-radical species generated by inner-sphere electron transfer of phosphine-coordinated Pd(0) species with alkyl bromide. This intriguing hybrid alkyl Pd(I)-radical species is elucidated by theoretical calculation to be a triplet species coordinated by three phosphine atoms
An efficient totalsynthesis of the chlorinated thiazole-containing natural product conulothiazole A is reported. Key features of this synthesis include a novel rhodium-catalyzed enantioselective hydrogenation of a 2-enamido-thiazole and a vinylic Finkelstein reaction that could be implemented at all stages of the synthesis to install the chlorinated alkene.
Catalyst-free and oxidant-free tandem aza-Mannich/cyclization/aromatization of <i>C</i>,<i>N</i>-cyclic azomethine imines with enamides: facile synthesis of 5,6-dihydropyrazolo[5,1-<i>a</i>]isoquinolines
作者:Hao Dong、Yongxing Zhang、Xiaochen Tian、Ruochen Pang、Weiwu Ren、Yang Wang
DOI:10.1039/d2gc01275h
日期:——
tandem aza-Mannich/cyclization/aromatization reaction of C,N-cyclic azomethine imines with enamides has been developed. This practical one-step protocol enables a simple and environmentally friendly route toward the straightforward synthesis of highly substituted 5,6-dihydropyrazolo[5,1-a]isoquinolines. Different types of enamides and enamines, especially enamides derived from marketed drugs as well as bioactive
开发了一种新型高效的无催化剂、无氧化剂串联氮杂曼尼希/环化/芳构化C , N-环偶氮甲亚胺与烯酰胺反应。这种实用的一步法为直接合成高度取代的 5,6-二氢吡唑并[5,1- a ] 异喹啉提供了一种简单且环保的途径。不同类型的烯酰胺和烯胺,尤其是衍生自上市药物以及生物活性分子的烯酰胺,是合适的底物。CB1 大麻素受体拮抗剂可以基于该方法有效合成,说明这将是合成有价值的结构基序的实用策略。
Photoenzymatic Conversion of Enamides to Enantioenriched Benzylic Amines Enabled by Visible-Light-Induced Single-Electron Reduction
The enantioselective reduction of enamides is an efficient and atom-economical way to construct chiral amine motifs. In contrast to transition-metal complex based asymmetrichydrogenation, an alternative biocatalytic way is more sustainable but remains unexploited. The challenge lies in the redox potential mismatch between the ground-state enzymes and abiotic enamide substrates. Herein, we report a