Syntheses of 1H-Indoles, Quinolines, and 6-Membered Aromatic N-Heterocycle-Fused Scaffolds via Palladium(II)-Catalyzed Aerobic Dehydrogenation under Alkoxide-Free Conditions was written by Yoo, Hyung-Seok;Yang, Yo-Sep;Kim, Soo Lim;Son, Seung Hwan;Jang, Yoon Hu;Shin, Jeong-Won;Kim, Nam-Jung. And the article was included in Chemistry – An Asian Journal in 2021.Quality Control of 6-Nitro-1H-indole This article mentions the following:
Aromatic N-heterocycle-fused scaffolds such as indoles and quinolines I (R1 = H, 5-Me, 6-NH2, etc.; R2 = H, 2-Me, 2-C6H5, etc.; X = C, N) are important core structures found in various bioactive natural products and synthetic compounds Recently, various dehydrogenation methods with the help of alkoxides, known to significantly promote dihydro- or tetrahydro-heterocycles to be oxidized, were developed for the heterocycle synthesis. However, these approaches are sometimes unsuitable due to resulting undesired side reactions such as reductive dehalogenation. Herein, expedient syntheses of 1H-indoles, quinolines, and 6-membered N-heterocycle-fused scaffolds from their hydrogenated forms through palladium(II)-catalyzed aerobic dehydrogenation under alkoxide-free conditions are reported. A total of 48 compounds were successfully synthesized with a wide range of functional groups including halogens (up to 99% yield). These methodologies provide facile routes for various privileged structures possessing aromatic N-heterocycles without the help of alkoxides, in highly efficient manners. In the experiment, the researchers used many compounds, for example, 6-Nitro-1H-indole (cas: 4769-96-4Quality Control of 6-Nitro-1H-indole).
6-Nitro-1H-indole (cas: 4769-96-4) belongs to indole derivatives. Indole exists overwhelmingly in the 1H-indole form as do other simple indoles.Indole was synthesized in moderate yield via an o-naphthoquinone catalyzed tandem cross-coupling of substituted aniline and benzylamine under aerobic oxidation conditions.Quality Control of 6-Nitro-1H-indole
Referemce:
Indole alkaloid derivatives as building blocks of natural products from Bacillus thuringiensis and Bacillus velezensis and their antibacterial and antifungal activity study,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles