Waste-Free Synthesis of Condensed Heterocyclic Compounds by Rhodium-Catalyzed Oxidative Coupling of Substituted Arene or Heteroarene Carboxylic Acids with Alkynes
of 2-amino- and 2-hydroxybenzoic acids with internal alkynes proceeds efficiently in the presence of a rhodium/copper catalyst system under air to afford the corresponding 8-substituted isocoumarinderivatives, some of which exhibit solid-state fluorescence. Depending on conditions, 4-ethenylcarbazoles can be synthesized selectively from 2-(arylamino)benzoic acids. The oxidative coupling reactions of
<i>tert</i>-Butyl Nitrite-Mediated Synthesis of <i>N</i>-Nitrosoamides, Carboxylic Acids, Benzocoumarins, and Isocoumarins from Amides
作者:Subhash L. Yedage、Bhalchandra M. Bhanage
DOI:10.1021/acs.joc.7b00570
日期:2017.6.2
(TBN) as a multitask reagent for (1) the controlled synthesis of N-nitrosoamide from N-alkyl amides, (2) hydrolysis of N-methoxyamides to carboxylic acids, (3) metal- and oxidant-free benzocoumarin synthesisfrom ortho-aryl-N-methoxyamides via N–H, C–N, and C–H bond activation, and (4) isocoumarin synthesisusingRu(II)/PEG as a recyclable catalytic system via ortho-C–H activation and TBN as an oxygen source