enantioselective formal [4+2] cycloadditions of 3‐nitroindoles are presented. By using 3‐nitroindoles in combination with an organocatalyst, chiral dihydrocarbazole scaffolds are formed in moderate to good yields (up to 87 %) and enantioselectivities (up to 97 % ee). The reaction was extended to include enantioselective [4+2] cycloadditions of 3‐nitrobenzothiophene. The reaction proceeds through a [4+2] cycl
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
Unprecedented access to functionalized pyrrolo[2,1-<i>a</i>]isoquinolines from the domino reaction of isoquinolinium ylides and electrophilic benzannulated heterocycles
作者:Sheba Ann Babu、Rajalekshmi A. R.、Nitha P. R.、Vishnu K. Omanakuttan、Rahul P.、Sunil Varughese、Jubi John
DOI:10.1039/d1ob00005e
日期:——
We have come across an unexpected reaction between electrophilic indoles and isoquinolinium methylides for accessingfunctionalized pyrrolo[2,1-a]isoquinolines. The reaction was found in general to yield the products in good yields. We also observed the formation of S–S-bridged bis-pyrrolo[2,1-a]isoquinolines from the reaction of 3-nitro benzothiophene and isoquinolinium methylides.
我们发现亲电吲哚和异喹啉鎓甲基化物之间发生意想不到的反应,以访问官能化的吡咯并[2,1- a ]异喹啉。通常发现该反应以良好的产率产生产物。我们还观察到3-硝基苯并噻吩与异喹啉鎓甲基化物的反应形成了S-S桥联的双吡咯并[2,1- a ]异喹啉。
Phosphine-catalyzed dearomative [3+2] annulation of 3-nitroindoles and allenoates
作者:Kui Liu、Gang Wang、Shao-Jie Cheng、Wen-Feng Jiang、Cheng He、Zhi-Shi Ye
DOI:10.1016/j.tetlet.2019.06.016
日期:2019.7
dearomative [3+2] annulation of 3-nitroindoles with allenoates has been successfully developed, providing a facile access to cyclopenta[b]indolines with good to excellent yields and high diastereoselectivities. This strategy features mild reaction conditions, high functional group tolerance, and scalability. Additionally, the 2-nitrobenzofuran and 2-nitrobenzothiophene were good dearomative [3+2] annulation
已经成功开发了有效的膦催化的3-硝基吲哚与脲基甲酸酯的脱芳族环氧化物[3 + 2]环化反应,可轻松获得环戊二烯[ b ]吲哚,并具有良好或优异的收率和较高的非对映选择性。该策略具有温和的反应条件,较高的官能团耐受性和可扩展性。此外,2-硝基苯并呋喃和2-硝基苯并噻吩是良好的脱芳香性[3 + 2]环空伙伴。
Atroposelective Synthesis of Axially Chiral 4-Aryl α-Carbolines via <i>N</i>-Heterocyclic Carbene Catalysis
作者:Rui Ma、Xiaoxue Wang、Qiaoyu Zhang、Lei Chen、Jian Gao、Jie Feng、Donghui Wei、Ding Du
DOI:10.1021/acs.orglett.1c01221
日期:2021.6.4
functional theory calculations were also conducted to illuminate the key factors for controlling the origin of the enantioselectivity. This strategy not only provides an efficient pathway to access axially chiral α-carboline atropisomers but also offers a novel catalyticenantioselective mode for the construction of axially chiral heterobiaryls by using NHC-bound alkynyl acylazoliums.