1334951-14-2Relevant academic research and scientific papers
Substitution of a nitro group by diazonium salts in σH-Adducts of carbanions to mono-nitrobenzenes. Formation of substituted azobenzenes and indazoles
Wróbel, Zbigniew,Wilk, Bogdan,Kwast, Andrzej
, (2021)
σH-Adducts formed at low temperature from nitrobenzene derivatives and carbanions stabilized by cyano, alkoxycarbonyl or sulfonyl groups react with benzenediazonium salts as nucleophiles, forming a new C–N bond preferentially at carbon atom bearing the nitro group. The so-formed intermediates eliminate HNO2 molecule under action of base, yielding substituted azobenzenes. Adducts of secondary carbanions, stabilized by cyano or sulfonyl groups to the ortho positions of nitrobenzenes, cyclize in situ to substituted indazoles. Some ortho σH-adducts of 1-chloroethyl phenyl sulfone carbanion add diazonium cations at meta position to the nitro group. In this case, the subsequent elimination of HCl leads to azo compounds retaining the nitro group in its original position.
A general and efficient approach to 2H-indazoles and 1H-pyrazoles through copper-catalyzed intramolecular N-N bond formation under mild conditions
Hu, Jiantao,Cheng, Yongfeng,Yang, Yiqing,Rao, Yu
, p. 10133 - 10135 (2011/10/09)
A new efficient copper-catalyzed intramolecular amination reaction has been developed to readily synthesise a wide variety of multi-substituted 2H-indazole and 1H-pyrazole derivatives from easily accessible starting materials under mild conditions. A highly selective ligand for estrogen receptor β was prepared in three steps by employing this method. The Royal Society of Chemistry 2011.
