Aromatic CC Bonds as Dipolarophiles: Facile Reactions of Uncomplexed Electron-Deficient Benzene Derivatives and Other Aromatic Rings with a Non-Stabilized Azomethine Ylide
作者:Sunyoung Lee、Sonia Diab、Pierre Queval、Muriel Sebban、Isabelle Chataigner、Serge R. Piettre
DOI:10.1002/chem.201201238
日期:2013.5.27
Non‐stabilized azomethineylide 4 a reacts smoothly at room temperature with a variety of uncomplexed aromatic heterocycles and carbocycles on the condition that the ring contains at least one or two electron‐withdrawing substituents, respectively. Aromatic substrates, including pyridine and benzene derivatives, participate as 2 π components in [3+2] cycloaddition reactions and interact with one, two
Palladium(0)-Catalyzed Dearomatization of 2-Nitrobenzofurans through Formal (3+2) Cycloadditions with Vinylcyclopropanes: A Straightforward Access to Cyclopenta[b]benzofurans
palladium-catalyzed dearomatization of electron-poor arenes, we report herein that various 2-nitrobenzofurans efficiently undergo a dearomative (3+2) cycloaddition with vinylcyclopropanes. This new method gives access to a wide variety of cyclopenta[b]benzofuran derivatives in a straightforward manner.
Copper(I)-Catalyzed Dearomative (3 + 2) Cycloaddition of 3-Nitroindoles with Propargylic Nucleophiles: An Access to Cyclopenta[<i>b</i>]indolines
作者:Johanne Ling、David Mara、Baptiste Roure、Maxime Laugeois、Maxime R. Vitale
DOI:10.1021/acs.joc.9b03459
日期:2020.3.6
The copper(I)-catalyzed dearomatization of 3-nitroindoles with propargylic nucleophiles is described. In mild reaction conditions, this original dearomative (3 + 2) cycloaddition process gives access to a wide variety of cyclopenta[b]indolines in good to excellent yields, with high functional group tolerance. The proof of concept that an enantioselective version of this reaction is accessible by employing
Catalyst-free formal [3 + 2] cycloaddition of stabilized <i>N</i>,<i>N</i>-cyclic azomethine imines to 3-nitrobenzofurans and 3-nitro-4<i>H</i>-chromenes: access to heteroannulated pyrazolo[1,2-<i>a</i>]pyrazoles
作者:Dmitry V. Osipov、Kirill S. Korzhenko、Daria A. Rashchepkina、Alina A. Artemenko、Oleg P. Demidov、Vadim A. Shiryaev、Vitaly A. Osyanin
DOI:10.1039/d1ob01377g
日期:——
We have studied the [3 + 2]-cycloaddition of various N,N-cyclic azomethineimines to 3-nitrobenzofurans. This process is a rare example of their dearomatization. We have also extended this process to the related 3-nitro-4H-chromenes as dipolarophiles. Both reactions provide access to benzofuro- and chromeno-condensed pyrazolo[1,2-a]pyrazoles with 100% atom economy in a diastereoselective manner under
我们研究了各种N,N-环状偶氮甲亚胺与 3-硝基苯并呋喃的 [3 + 2]-环加成反应。这个过程是它们脱芳构化的一个罕见例子。我们还将这一过程扩展到相关的 3-nitro-4 H - chromenes 作为亲偶极体。这两种反应都提供了在温和的环保条件下以非对映选择性方式获得具有 100% 原子经济性的苯并呋喃和色烯并缩合吡唑并[1,2- a ]吡唑。最后,在DFT计算的基础上,给出了对上述[3 + 2]-环加成的机理见解,并解释了该方法的实验确定的局限性。推拉杂环的赫希菲尔德原子电荷值被建议作为先验的标准评估它们与N , N -环偶氮甲碱亚胺偶极环加成的可能性。
Dearomatization of 3‐Nitroindoles with Highly γ‐Functionalized Allenoates in Formal (3+2) Cycloadditions
作者:Léo Birbaum、Laurent Gillard、Hélène Gérard、Hassan Oulyadi、Guillaume Vincent、Xavier Moreau、Michael De Paolis、Isabelle Chataigner
DOI:10.1002/chem.201903455
日期:2019.10.28
3-Nitroindoles are easily reacted with highly substituted γ-allenoates in the presence of a commercially available phosphine catalyst. For instance, allenoates derived from biomolecules such as amino and deoxycholic acids are combined for the first time with 3-nitroindole. The corresponding dearomatized (3+2) tricyclic cycloadducts are obtained as α-regioisomers exclusively. DFT computations shed light