Synthesis of 3-Substituted Indazoles from Arynes and N-Tosylhydrazones
摘要:
Readily available, stable, and inexpensive N-tosylhydrazones react with arynes under mild reaction conditions to afford 3-substituted indazoles in moderate to good yields. The reaction appears to involve a dipolar cycloaddition of in situ generated diazo compounds and arynes.
Synthesis of 3-Substituted Indazoles from Arynes and <i>N</i>-Tosylhydrazones
作者:Pan Li、Jingjing Zhao、Chunrui Wu、Richard C. Larock、Feng Shi
DOI:10.1021/ol201086g
日期:2011.7.1
Readily available, stable, and inexpensive N-tosylhydrazones react with arynes under mild reaction conditions to afford 3-substituted indazoles in moderate to good yields. The reaction appears to involve a dipolar cycloaddition of in situ generated diazo compounds and arynes.
v. Auwers; Huettenes, Chemische Berichte, 1922, vol. 55, p. 1135
作者:v. Auwers、Huettenes
DOI:——
日期:——
Synthesis of Substituted 1<i>H</i>-Indazoles from Arynes and Hydrazones
作者:Pan Li、Chunrui Wu、Jingjing Zhao、Donald C. Rogness、Feng Shi
DOI:10.1021/jo202598e
日期:2012.4.6
The 1H-indazole skeleton can be constructed by a [3 + 2] annulation approach from arynes and hydrazones. Under different reaction conditions, both N-tosylhydrazones and N-aryl/alkylhydrazones can be used to afford a variety of indazoles. The former reaction affords 3-substituted indazoles either via in situ generated diazo compounds or through an annulation/elimination process. The latter reaction leads to 1,3-disubstituted indazoles likely through an annulation/oxidation process. The reactions operate under mild conditions and can accommodate aryl, vinyl, and less satisfactorily, alkyl groups.