Transition Metal-Free De Novo Synthesis of Sulfonated Pyrazoles from Sulfonyl Hydrazides, 1,3-Diketones, and Sodium Sulfinates at Room Temperature
作者:Jiawen Chen、Dongwei Chen、Jinqiang Kuang、Yongmin Ma
DOI:10.1021/acs.joc.1c00171
日期:2021.7.16
A transition metal-free method for de novo construction of diverse sulfonated pyrazoles from readily available sulfonyl hydrazides, 1,3-diketones, and sodiumsulfinates was established under mild conditions. Pyrazoles bearing two different sulfonyl groups were obtained in one step. The method features a diversity of substituents of the pyrazole products and a remarkably simple work-up.
Domino C-H Sulfonylation and Pyrazole Annulation for Fully Substituted Pyrazole Synthesis in Water Using Hydrophilic Enaminones
作者:Yanhui Guo、Guodong Wang、Li Wei、Jie-Ping Wan
DOI:10.1021/acs.joc.8b02897
日期:2019.3.1
NH2-functionalized enaminones and sulfonyl hydrazines have been developed for the synthesis of fully substituted pyrazoles. By making use of the hydrophilic primary amino group in the enaminones, the reactions proceed well in the medium of pure water in the presence of molecular iodine, TBHP, and NaHCO3 via cascade C-H sulfonylation and pyrazole annulation. The cleavage of the C–N bond in enaminones is confirmed
Dual Roles of Sulfonyl Hydrazides: A Three-Component Reaction To Construct Fully Substituted Pyrazoles Using TBAI/TBHP
作者:Jie Zhang、Ying Shao、Hongxiang Wang、Qiang Luo、Jijun Chen、Dongmei Xu、Xiaobing Wan
DOI:10.1021/ol501312s
日期:2014.6.20
A mild and rapid approach has been developed for the construction of fully substituted pyrazoles using TBAI as a catalyst and TBHP as an oxidant, in which tosylhydrazide functions as the ring component and sulfonyl precursor. This protocol features a wide substrate scope with a broad range of functional group tolerance, utilizes easily available starting materials, can be scaled-up, and is operationally simple.