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
Copper-Catalyzed Double C–H Alkylation of Aldehyde-Derived <i>N</i>,<i>N</i>-Dialkylhydrazones with Polyhalomethanes: Flexible Access to 4-Functionalized Pyrazoles
作者:Alexis Prieto、Didier Bouyssi、Nuno Monteiro
DOI:10.1021/acscatal.6b02439
日期:2016.10.7
have been made accessible in a single step from readily available aldehyde-derived N,N-dialkyl hydrazones and functionalized polyhalomethane derivatives. The process is believed to follow copper-catalyzed cascade C(sp2)–H haloalkylation/C(sp3)–H cyclization/aromatization reaction sequences.