Synthesis of 3-(Tosylalkyl)indazoles and their Desulfonylation Reactions - A New Entry to 3-Substituted Indazoles by an Unprecedented Friedel-Crafts Process
作者:Silvia Campetella、Alessandro Palmieri、Marino Petrini
DOI:10.1002/ejoc.200900222
日期:2009.7
Reaction of indazoles with aldehydes in the presence of p-toluenesulfinic acid affords the corresponding sulfonyl indazoles in satisfactory yields. The reported Friedel–Crafts process is rather unusual on indazoles because of the reduced electronic density of the heterocycle. The obtained sulfonyl indazoles can be desulfonylated under reductive conditions, finally leading to 3-alkylated indazoles.(©
在对甲苯亚磺酸存在下,吲唑与醛反应以令人满意的产率得到相应的磺酰基吲唑。由于杂环的电子密度降低,报道的 Friedel-Crafts 过程在吲唑上相当不寻常。所得磺酰基吲唑可在还原条件下脱磺酰化,最终生成 3-烷基化吲唑。 (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)