Two consecutive N-heterocyclic carbene (NHC) catalytic systems were combined in a one-pot cascade reaction for the assembly of aromatic aldehydes and 2-haloenals into a structurally complex γ-lactone backbone.
Carbene-Catalyzed Enantioselective Addition of Benzylic Carbon to Unsaturated Acyl Azolium for Rapid Synthesis of Pyrrolo[3,2-<i>c</i>]quinolines
作者:Jilan Wang、Yongjia Li、Jun Sun、Hongling Wang、Zhichao Jin、Yonggui Robin Chi
DOI:10.1021/acscatal.8b02651
日期:2018.10.5
A carbene-catalyzed enantioselective addition of benzylic carbon to α,β-unsaturated acyl azolium intermediate generated via N-heterocyclic carbene catalysis is disclosed. This addition is followed by a stereoselective Mannich reaction and a chemo-selective lactamformation cascade to afford pyrrolo[3,2-c]quinolones as the products with excellent yields and optical purities. This work constitutes an
公开了卡宾催化的苯甲基碳的对映选择性加成到通过N-杂环卡宾催化产生的α,β-不饱和酰基偶氮中间体上。该添加之后是立体选择性曼尼希反应和化学选择性内酰胺形成级联,以提供吡咯并[3,2- c ]喹诺酮作为具有优异收率和光学纯度的产物。这项工作构成有效的不对称苄基sp 3-碳官能化和一步一步快速进入带有四个连续手性中心的多环杂环。
Enantio- and Diastereoselective Synthesis of Chromeno[4,3-<i>b</i>]pyrrole Derivatives Bearing Tetrasubstituted Chirality Centers through Carbene Catalyzed Cascade Reactions
作者:Tingting Li、Jilan Wang、Jun Xu、Jiamiao Jin、Yonggui Robin Chi、Zhichao Jin
DOI:10.1021/acs.orglett.9b04371
日期:2020.1.3
An NHC-catalyzed cascade cycloaddition reaction is developed for quick access to structurally sophisticated tetrahydrochromeno[4,3-b]pyrrole derivatives. A sterically congested tetrasubstituted chirality carbon center is formed during the cyclization process. All the α-, β-, and carbonyl carbons of the enal substrates are functionalized in chemo- and stereoselective fashion. The multicyclic chromeno[4
Asymmetric Synthesis of Enantioenriched 6-Hydroxyl Butyrolactams Promoted by N-Heterocyclic Carbene
作者:Zhouli Hu、Ying Zhu、Zhenqian Fu、Wei Huang
DOI:10.1021/acs.joc.9b01490
日期:2019.8.16
Herein, an efficient route to synthesize 6-hydroxyl butyrolactams has been successfully developed via an N-heterocycliccarbene-catalyzed formal [3 + 2] annulation of bromoenals with α-amino ketones, followed by reduction. Remarkably, enantioenriched epi-neoclausenamide, which is one of the clausenamide derivatives, could be efficiently prepared by this strategy.
Conjugated Dienyne‐Imides as Robust Precursors of 1‐Azatrienes for 6π Electrocyclizations to Furo[2,3‐
<i>b</i>
]dihydropyridine Cores
作者:Yanjun Wan、Xuchun Zheng、Cheng Ma
DOI:10.1002/anie.201800303
日期:2018.5.4
intermediates for 6πelectrocyclizations was developed by using readily accessible dienyne‐imides and various terminal olefins under PdII catalysis. Taking advantage of the sequential cooperation between preloaded and incorporated functional handles at 1,3‐dien‐5‐yne skeletons, this method not only enables the selective generation of putative 1‐azatrienes but significantly accelerates their thermal 6π‐electrocyclic
通过在Pd II催化下使用易得的二烯炔-酰亚胺和各种末端烯烃,开发了一种新的策略来生成用于6π电环化的功能化1-氮杂三烯中间体。利用这种方法,可以在1,3-dien-5-yne骨架上预先加载和合并功能手柄之间的顺序配合,不仅可以选择性地生成假定的1-氮杂氮杂环丁烷,而且还可以显着加速其6π-电热环闭环反应的过程。一系列高产率的呋喃[2,3- b ]二氢吡啶衍生物。