The synthesis of N-alkyl-1H-1,2,4-triazoles from N,N-dialkylhydrazones and nitriles via formal [3+2] cycloaddition including the C-chlorination/nucleophilic addition/cyclisation/dealkylation sequence was developed. This sequential reaction utilising the in situ generation of hydrazonoyl chloride based on the ambiphilic reactivity of hydrazones afforded a variety of multi-substituted N-alkyl-triazoles
Synthesis of <i>o</i>-(Dimethylamino)aryl Ketones, Acridones, Acridinium Salts, and 1<i>H</i>-Indazoles by the Reaction of Hydrazones and Arynes
作者:Anton V. Dubrovskiy、Richard C. Larock
DOI:10.1021/jo302378w
日期:2012.12.21
A novel, efficient route to biologically and pharmaceutically important o-(dimethylamino)aryl ketones, acridones, acridinium salts, and 1H-indazoles has been developed starting from readily available hydrazones of aldehydes and o-(trimethylsilyl)aryl triflates. The reaction proceeds through arynes under mild conditions, tolerates a wide range of functional groups, and provides the final products in
One-pot synthesis of 1-alkyl-1H-indazoles from 1,1-dialkylhydrazones via aryne annulation
作者:Nataliya A. Markina、Anton V. Dubrovskiy、Richard C. Larock
DOI:10.1039/c2ob07117g
日期:——
The reaction of readily accessible 1,1-dialkylhydrazones with commercially available o-(trimethylsilyl)aryl triflates provides a direct one-step route to pharmaceutically important 1-alkylindazoles. The products are obtained in high yields by one-pot NCS-chlorination/aryne annulation or Ac2O-acylation/deprotection/aromatization protocols.