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.
Design and Application of New Imidazolylsulfonate-Based Benzyne Precursor: An Efficient Triflate Alternative
作者:Szabolcs Kovács、Ádám I. Csincsi、Tibor Zs. Nagy、Sándor Boros、Géza Timári、Zoltán Novák
DOI:10.1021/ol300529j
日期:2012.4.20
cycloadditions involving benzyne intermediates. The precursor offers an efficient alternative for generating benzynes compared to widely used ortho TMS triflates under similar reaction conditions. With the utilization of this new precursor, the formation of potentially genotoxic trifluoromethanesulfonate side product is eliminated. The applicability of the new benzyneprecursor was demonstrated in different
Rhodium‐Catalysed Selective C−H Allylation of 1<i>H</i>‐Indazoles with Vinylethylene Carbonate: Easily Introducing Allylic Alcohol
作者:Xiang Zhao、Junwei Huang、Yadong Feng、Xiuling Cui
DOI:10.1002/ejoc.202300823
日期:2023.10.21
An efficient rhodium(III)-catalyzed C−H bond activation/allylation reaction of 3-aryl-1H-indazoles with easily available vinylethylene carbonate has been reported. A series of allyl alcohol substituted 3-aryl-1H-indazoles were obtained.
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.