Iridium(<scp>iii</scp>)-catalysed annulation of pyrazolidinones with propiolates: a facile route to pyrazolo[1,2-<i>a</i>] indazoles
作者:Zi Yang、Zhenyu Song、Lianghua Jie、Lianhui Wang、Xiuling Cui
DOI:10.1039/c9cc02232e
日期:——
A facile synthesis of various pyrazolo[1,2-a] indazoles from pyrazolidinones and propiolates via iridium(III)-catalysed C–H bond activation/subsequent [4+1] cyclization has been developed. The reaction proceeds smoothly under mild reactionconditions and propiolates act as a novel C1 synthon. This transformation represents a redox-neutral process, exhibits a highly regioselectivity, and tolerates various
已经开发了一种通过铱(III)催化的C–H键活化/随后的[4 + 1]环化反应从吡唑啉酮和丙酸酯轻松合成各种吡唑并[1,2- a ]吲唑的方法。在温和的反应条件下,反应平稳进行,丙酸酯作为新型C 1合成子。该转变代表氧化还原中性过程,表现出高度的区域选择性,并能耐受各种官能团。
Selective Synthesis of 3‐(α‐Fluorovinyl)indoles and 3‐Acylindoles via the Cascade Reactions of 1‐Phenylpyrazolidinones with α,α‐Difluoromethylene Alkynes
作者:Yujie Yang、Na Li、Jie Zhao、Yuqin Jiang、Xinying Zhang、Xuesen Fan
DOI:10.1002/adsc.202100441
日期:2021.7.20
Presented herein is a selective synthesis of 3-(α-fluorovinyl)indoles and 3-acylindoles via the coupling of 1-phenylpyrazolidinones with α,α-difluoromethylene alkynes. Mechanistically, the formation of 3-(α-fluorovinyl)indoles is resulted from a cascade process including Rh(III)-catalyzed ortho-C−H bond cleavage, regioselective triple bond insertion, pyrazolidinone ring-opening, indole ring-formation
Construction of Pyridazine Analogues <i>via</i>
Rhodium-mediated C-H Activation
作者:Chao Yang、Feifei Song、Jiean Chen、Yong Huang
DOI:10.1002/adsc.201700905
日期:2017.10.25
Herein a rhodium (III)‐mediated catalysis was demonstrated for approaching the structurally divergent N,N‐bicyclic pyridazine analogues. The pyrazolidinone moiety was used to direct the ortho C−H activation and this led to a general synthesis of benzopyridazine analogues with satisfactory yields. The crucial effect of the base was illustrated in the sequential dehydration process. For mechanistic insight
Synthesis of Dihydroquinolinone Derivatives via the Cascade Reaction of <i>o</i>-Silylaryl Triflates with Pyrazolidinones
作者:Mengyang Shen、Jie Zhao、Yuanshuang Xu、Xinying Zhang、Xuesen Fan
DOI:10.1021/acs.joc.1c01814
日期:2021.11.5
Presented herein is a novel synthesis of dihydroquinolinone derivatives through an unprecedented cascadereaction of o-silylaryl triflates with pyrazolidinones. Mechanistically, the formation of the title products is believed to involve a cascade procedure including in situ formation of aryne and its addition with pyrazolidinone followed by N–N bond cleavage and intramolecular C–C bond formation/annulation
Catalytic System‐Controlled Divergent Reaction Strategies for the Construction of Diversified Spiropyrazolone Skeletons from Pyrazolidinones and Diazopyrazolones
作者:Feifei Fang、Shulei Hu、Chunpu Li、Qian Wang、Run Wang、Xu Han、Yu Zhou、Hong Liu
DOI:10.1002/anie.202105857
日期:2021.9.20
system-controlled divergent reaction strategy was here reported to construct four types of intriguing spiroheterocyclic skeletons from simple and readily available starting materials via a precise chemical bond activation/[n+1] annulation cascade. The tetraazaspiroheterocyclic and trizazspiroheterocyclic scaffolds could be independently constructed by a selective N−N bond activation/[n+1] annulation cascade, a C(sp2)-H
本文报道了一种催化系统控制的发散反应策略,通过精确的化学键活化/[ n +1] 环化级联,从简单易得的起始材料构建四种有趣的螺杂环骨架。四氮杂螺杂环和三氮杂螺杂环支架可以通过选择性 NN 键激活/[ n +1] 环化级联、C(sp 2 )-H 激活/[4+1] 环化和新型串联 C(sp 2 )-H/C(sp 3)−H 键活化/[4+1] 环化策略,以及广泛的底物、中等至优异的产率和有价值的转化。更重要的是,在这些转化中,我们首次捕捉到了不同催化体系下吡唑烷酮的 NN键活化和 C(sp 3 )-H 键活化。