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
Intramolecular Iodine-Mediated Oxygen Transfer from Nitro Groups to C≡C Bonds
作者:Inga Cikotiene
DOI:10.1002/ejoc.201200100
日期:2012.5
from nitrogroups to C≡C bonds has been achieved by employment of iodine monochloride or molecular iodine. The precursors are heterocyclic, aromatic or acyclic compounds, each bearing a nitrogroup ortho to an internal alkyne. The developed methodology is general for the preparation of a wide range of fused isoxazoles, each bearing a carbonyl function in the fifth position in the isoxazole ring. It
Interrupting the [Au]-Catalyzed Nitroalkyne Cycloisomerization: Trapping the Putative α-Oxo Gold Carbene with Benzo[<i>c</i>]isoxazole
作者:Pawan S. Dhote、Chepuri V. Ramana
DOI:10.1021/acs.orglett.1c00539
日期:2021.4.2
interrupted by possible trapping of the postulated intermediate α-oxo gold carbene with an external nucleophile such as benzo[c]isoxazole (anthranil). At the outset, this provides a simple synthesis of highly functionalized 3-acyl-(2-formylphenyl)-2H-indazoles with the sequential C–O, C–N, and N–N bond formations. This provides indirect support for the existence of α-oxo gold carbenes in the [Au]-catalyzed internal
通过假想的中间体α-氧代金卡宾可能被外部亲核试剂(例如苯并[ c ]异恶唑(蒽))捕获,从而中断了导致蒽基的2-炔基硝基苯的Au催化硝基炔环异构化。首先,它提供了具有连续C–O,C–N和N–N键形成的高度官能化的3-酰基-(2-甲酰基苯基)-2 H-吲唑的简单合成方法。这为在α-催化的炔炔的内部氧化还原过程中α-氧羰金的存在提供了间接支持。
Catalytic asymmetric formal [3+2] cycloaddition of isatogens with azlactones to construct indolin-3-one derivatives
作者:Lihua Xie、Yi Li、Shunxi Dong、Xiaoming Feng、Xiaohua Liu
DOI:10.1039/d0cc06418a
日期:——
A number of enantioenriched indolin-3-one derivatives were readily obtained by chiral guanidine-catalyzed [3+2] cycloaddition of isatogens with azlactones.
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。