Electrooxidation Enables Selective Dehydrogenative [4+2] Annulation between Indole Derivatives
作者:Chunlan Song、Kun Liu、Xu Jiang、Xin Dong、Yue Weng、Chien‐Wei Chiang、Aiwen Lei
DOI:10.1002/anie.202000226
日期:2020.4.27
route to highlyfunctionalized pyrimido[5,4-b]indoles under oxidant- and metal-free conditions. Notably, this electrochemical approach maintains excellent functional-group tolerance and can be extended as a modification tactic for pharmaceutical research. Preliminary mechanism studies indicate that the electrooxidation annulation proceeds through radical-radical cross-coupling between an indole radical
Direct, enantioselective synthesis of pyrroloindolines and indolines from simple indole derivatives
作者:Jane Ni、Haoxuan Wang、Sarah E. Reisman
DOI:10.1016/j.tet.2013.04.003
日期:2013.7
The (R)-BINOL·SnCl4-catalyzed formal (3+2) cycloaddition between 3-substituted indoles and benzyl 2-trifluoroacetamidoacrylate is a direct, enantioselective method to prepare pyrroloindolines from simple starting materials. However, under the originally disclosed conditions, the pyrroloindolines are formed as mixtures of diastereomers, typically in the range of 3:1 to 5:1 favoring the exo-product. The
( R )-BINOL·SnCl 4催化的 3-取代吲哚与 2-三氟乙酰氨基丙烯酸苄酯之间的形式 (3+2) 环加成反应是一种直接的、对映选择性的方法,可从简单的起始原料制备吡咯并二氢吲哚。然而,在最初公开的条件下,吡咯并二氢吲哚形成为非对映异构体的混合物,通常在3:1至5:1的范围内,有利于外型产物。差的非对映选择性有损于反应的合成效用。我们在此报告了 2-三氟乙酰氨基丙烯酸甲酯与 ( R )-3,3'-二氯-BINOL·SnCl 4 结合使用提供具有改进的非对映选择性(通常≥10:1)的相应吡咯并二氢吲哚。在机理研究的指导下,还描述了通过原位还原持久性亚胺离子来合成富含对映体二氢吲哚的单瓶合成。
Asymmetric Synthesis of Furo[3,4‐
<i>b</i>
]indoles by Catalytic [3+2] Cycloaddition of Indoles with Epoxides
A highly efficient N,N′‐dioxide–NiII catalyst system for the catalytic [3+2] cycloaddition of indoles with epoxides through CC cleavage of oxiranes was accomplished under mild conditions. It provided a promising approach for chiral furo[3,4‐b]indoles in up to 98 % yield with up to 91 % enantiomeric excess (ee) and >95:5 diastereomeric ratio (d.r.).
一个高效Ñ,Ñ '二氧化物-镍II为吲哚与环氧化物至C催化的[3 + 2]环加成催化剂体系环氧乙烷的C ^裂解温和的条件下完成的。它为手性呋喃[3,4- b ]吲哚提供了一种有前途的方法,产率高达98%,对映体过量(ee)高达91%,非对映体比率(dr)大于95:5。
Catalytic Asymmetric Synthesis of Pyrroloindolines via a Rhodium(II)-Catalyzed Annulation of Indoles
作者:Jillian E. Spangler、Huw M. L. Davies
DOI:10.1021/ja4025337
日期:2013.5.8
Herein we report the synthesis of pyrroloindolines via a catalytic enantioselective formal [3+2] cycloaddition of C(3)-substituted indoles. This methodology utilizes 4-aryl-1-sulfonyl-1,2,3-triazoles as carbenoid precursors and the rhodium(II)-tetracarboxylate catalyst Rh2(S-PTAD)4. A variety of aryl-substituted pyrroloindolines were prepared in good yields and with high levels of enantioinduction
An efficient catalytic asymmetric intermolecular C2 Friedel-Craftsalkylation reaction between N-methyl skatole and beta,gamma-unsaturated alpha-ketoesters has been realized by a chiral N,N'-dioxide-Ni(II) complex. The corresponding indole derivatives were obtained in good yield (up to 96%) with excellent enantioselectivities (up to 99% ee) under mild reaction conditions.