Lewis Acid-catalyzed [3 + 2]Cyclo-addition of Alkynes with<i>N</i>-Tosyl-aziridines via Carbon–Carbon Bond Cleavage: Synthesis of Highly Substituted 3-Pyrrolines
作者:Lei Li、Junliang Zhang
DOI:10.1021/ol202603e
日期:2011.11.18
A novel, efficient, and highly regioselective Lewis acid-catalyzed [3 + 2] cycloaddition of alkynes with azomethine ylides, which are easily obtained from N-tosylaziridines via C–C bond heterolysis at room temperature was developed. Moderate enantioselectivity (70% ee) can be achieved by the application of the commercially available chiral Pybox 7 as the ligand.
Construction of thiazines and oxathianes via [3 + 3] annulation of N-tosylaziridinedicarboxylates and oxiranes with 1,4-dithiane-2,5-diol: application towards the synthesis of bioactive molecules
作者:Rohit Kumar Varshnaya、Prabal Banerjee
DOI:10.1039/c7ob00941k
日期:——
Lewis acid catalyzed [3+3] annulation of N tosylaziridinedicarboxylates and oxiranes with in situ generated mercaptoaldehyde for the synthesis of functionalized thiazine and oxathiane derivatives has been developed. Additionally, this method facilitate the derivatization of thiazine by detosylation and Krapcho monodecarboxylation.
Synthesis of polycyclic spiroindolines <i>via</i> the cascade reaction of 3-(2-isocyanoethyl)indoles
作者:Haizhen Li、Jinyu Wu、Jianfeng Zheng、Wei-Dong Z. Li
DOI:10.1039/d1cc04576h
日期:——
Tandem reactions of the yttrium(iii) catalyzed ring-opening reaction of 2,2′-diester aziridines with 3-(2-isocyanoethyl)indoles and the subsequent Friedel–Crafts/Mannich/desulfonylation were reported. A series of polycyclic spiroindolines containing tetrahydro-β-carbolines were obtained in moderate to excellent yields (56–92%) in one step under mild reaction conditions. A possible catalytic mechanism
报道了钇 ( iii ) 催化 2,2'-二酯氮丙啶与 3-(2-异氰乙基) 吲哚的开环反应和随后的 Friedel-Crafts/Mannich/脱磺酰化反应的串联反应。在温和的反应条件下,一步获得了一系列含有四氢-β-咔啉的多环螺二氢吲哚,收率中等至极好(56-92%)。还提出了可能的催化机制。
Metal-free anomalous [5+1] cycloaddition reactions of donor–acceptor aziridines for the synthesis of 2<i>H</i>-1,4-oxazines
A new type of metal-free [5+1] cycloaddition reaction of donor–acceptor aziridines with 2-(2-isocyanoethyl)indoles is reported herein. This method exhibits broad substrate scope and atom-economy. A series of 2H-1,4-oxazines containing an indole heterocycle skeleton were obtained in up to 92% yield under mild reaction conditions. Control experiments revealed that free indole N–H is crucial for the above
本文报道了供体-受体氮丙啶与2-(2-异氰乙基)吲哚的新型无金属[5+1]环加成反应。该方法表现出广泛的底物范围和原子经济性。在温和的反应条件下,得到了一系列含有吲哚杂环骨架的2 H -1,4-恶嗪,收率高达92%。对照实验表明,游离吲哚 N-H 对于上述转化至关重要。理论计算研究为深入了解反应机理提供了指导,并确定了游离吲哚N-H和羰基之间的氢键,以降低过渡态的自由能垒。