Efficient Nucleophilic Aromatic Substitution between Aryl Nitrofluorides and Alkynes
摘要:
The nucleophilic aromatic substitution reaction between electron-deficient aryl fluorides and terminal alkynes is shown to be efficiently promoted by sodium bis(trimethylsilyl)amide as a base. Moderate to excellent yields of 2-ethynylnitrobenzene products can be obtained under mild conditions.
Copper(0)/PPh<sub>3</sub>-Mediated Bisheteroannulations of <i>o</i>-Nitroalkynes with Methylketoximes Accessing Pyrazo-Fused Pseudoindoxyls
作者:Huanxin Meng、Zhenhua Xu、Zhonghua Qu、Huawen Huang、Guo-Jun Deng
DOI:10.1021/acs.orglett.0c02180
日期:2020.8.7
A copper(0)/PPh3-mediated cascade bisheteroannulation reaction of o-nitroalkynes with methylketoximes has been developed that provides viable access to a diverse range of pyrazo-fused pseudoindoxyl compounds. Synthetically useful functional groups including sensitive C–I bonds are compatible with this system. Mechanistic studies suggest a reaction cascade involving sequential PPh3-mediated deoxygenative
Electrochemically Enabled Selenium Catalytic Synthesis of 2,1-Benzoxazoles from <i>o</i>-Nitrophenylacetylenes
作者:Lin-Wei Wang、Yu-Feng Feng、Hong-Min Lin、Hai-Tao Tang、Ying-Ming Pan
DOI:10.1021/acs.joc.1c00012
日期:2021.11.19
reported an electrochemically mediated method for the preparation of 2,1-benzoxazoles from o-nitrophenylacetylenes. Different from the traditional electrochemical reduction of nitro to nitroso, the nitro group directly underwent a cyclization reaction with the alkyne activated by selenium cation generated by the anodic oxidation of diphenyldiselenide and finally produced the desired products.
Energy Transfer Photocatalytic Radical Rearrangement in <i>N</i>-Indolyl Carbonates
作者:Milan Bera、Ho Seong Hwang、Tae-Woong Um、Soo Min Oh、Seunghoon Shin、Eun Jin Cho
DOI:10.1021/acs.orglett.2c00085
日期:2022.3.11
A new type of sp3-like N-centered radical has been generated by selective energy transfer catalysis. Upon photoexcitation, homolytic N–O bond cleavage of N-indolyl carbonate in the presence of an Ir complex produced N- and O-centered radicals. The high spin density at the C3 position of indole led to radical recombination with the O-centered radical, affording valuable 3-oxyindole derivatives without
通过选择性能量转移催化产生了一种新型的sp 3类N 中心自由基。在光激发下,在 Ir 配合物存在下N-吲哚碳酸酯的均裂 N-O 键断裂产生以 N 和 O 为中心的自由基。吲哚 C3 位的高自旋密度导致自由基与以 O 为中心的自由基复合,从而提供有价值的 3-氧吲哚衍生物而无需脱羧。还证明了所需产物向各种分子的转化。
Synthesis of Hydroxysuccinimide Substituted Indolin-3-ones via One-Pot Cascade Reaction of <i>o</i>-Alkynylnitrobenzenes with Maleimides under Au(III)–Cu(II) Relay/Synergetic Catalysis
作者:Guang Chen、Yue Wang、Jie Zhao、Xinying Zhang、Xuesen Fan
DOI:10.1021/acs.joc.1c01485
日期:2021.11.5
Presented herein is a one-pot cascade reaction of o-alkynylnitrobenzenes with maleimides leading to the formation of hydroxysuccinimide substituted indolin-3-ones under Au(III)–Cu(II) relay/synergetic catalysis. Mechanistically, the formation of the title products involves an unprecedented cascade process including (1) nitro–alkyne cycloisomerization of o-alkynylnitrobenzene to give isatogen; (2) [3
本文介绍的是邻炔基硝基苯与马来酰亚胺在 Au(III)-Cu(II) 中继/协同催化下形成羟基琥珀酰亚胺取代的 indolin-3- one 的一锅级联反应。从机理上讲,标题产物的形成涉及前所未有的级联过程,包括 (1) o的硝基-炔烃环异构化-炔基硝基苯,得到等离子;(2) isatogen与马来酰亚胺的[3+2]偶极环加成;(3)原位形成的异恶唑烷部分在中性条件下开环。值得注意的是,具有各种官能团的多种底物与反应条件相容,可以得到一系列高价值的杂化化合物,具有良好的效率和优异的原子经济性。此外,由此获得的产物可以很容易地转化为相应的马来酰亚胺取代的二氢吲哚-3-酮。重要的是,一些产品在人类癌细胞系中表现出显着的抗增殖活性。
PPh
<sub>3</sub>
‐Mediated Wittig‐Like/Mannich Tandem Reactions of 2‐Alkynylnitrobenzenes with Ketones for the Synthesis of 2,2‐Disubstituted Indolin‐3‐Ones
A synthetic strategy for the construction of 2,2-disubstituted indolin-3-ones from 2-alkynylnitroarenes and ketones has been described. The corresponding indolin-3-one derivatives were afforded in moderate to excellent product yields by using mild conditions. After a Wittig-like process, the key intermediates 3H-indol-3-ones were generated from 2-alkynylnitroarenes, which could be further transformed