Perfluoroalkylation of Aryl-<i>N</i>,<i>N</i>-dimethyl Hydrazones Using Hypervalent Iodine(III) Reagents or Perfluoroalkyl Iodides
作者:Benjamin Janhsen、Armido Studer
DOI:10.1021/acs.joc.7b00934
日期:2017.11.17
Radical trifluoromethylation of aryl N,N-dimethyl hydrazones using TBAI as an initiator and Togni’s reagent as a trifluoromethyl radical source is described. Cascades proceed via electron-catalysis; this approach is generally more applicable to hydrazone perfluoroalkylation using perfluoroalkyl iodides as the radical precursors in combination with a base under visible-light initiation.
Hydrazone as the Directing Group for Ir-Catalyzed Arene Diborylations and Sequential Functionalizations
作者:Abel Ros、Rocío López-Rodríguez、Beatriz Estepa、Eleuterio Álvarez、Rosario Fernández、José M. Lassaletta
DOI:10.1021/ja300308c
日期:2012.3.14
The use of hemilabile pyridine-hydrazone N,N-ligands allows the highlyselective Ir-catalyzed ortho,ortho'-directed diborylation of aromatic N,N-dimethylhydrazones in near-quantitative yields. One-pot sequential Suzuki-Miyaura cross-coupling with different arylbromides provides a short entry to unsymmetrically substituted 2,6-diarylbenzaldehyde derivatives.
使用 hemilabile 吡啶-腙 N,N-配体允许以接近定量的产率对芳香族 N,N-二甲基腙进行高度选择性的 Ir 催化的邻、邻'-定向二硼化。与不同芳基溴化物的一锅顺序 Suzuki-Miyaura 交叉偶联为不对称取代的 2,6-二芳基苯甲醛衍生物提供了一个捷径。
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
The Cu-catalyzed direct difluoroalkylation of aldehyde hydrazones with functionalized difluoromethyl bromides is described. The reaction yields stereodefined α,α–difluoro-β-keto hydrazones under mild conditions and can be carried out at a scale that opens up the possibility of practical applications.
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.