Bronsted-Acid-Promoted Rh-Catalyzed Asymmetric Hydrogenation of N-Unprotected Indoles: A Cocatalysis of Transition Metal and Anion Binding was written by Wen, Jialin;Fan, Xiangru;Tan, Renchang;Chien, Hui-Chun;Zhou, Qinghai;Chung, Lung Wa;Zhang, Xumu. And the article was included in Organic Letters in 2018.Safety of 2-Methyl-6-nitro-1H-indole This article mentions the following:
In the presence of [Rh(cod)Cl]2, the thiourea-substituted ferrocenyldiphosphine ZhaoPhos, and HCl in AcOH, 2-alkyl- and 2,3-dialkyl-substituted N-unprotected indoles underwent diastereoselective and enantioselective hydrogenation to yield nonracemic indolines such as (S)-2-methylindoline and (S,S)-2,3-dimethylindoline in 48-99% yields and 82-98% ee; hydrogenation of 6-nitro-2-methylindole and 2-phenylindole gave products in low or no yield. DFT calculations of the relative free energies of transition states and intermediates in the hydrogenation of 2-methylindole support an outer-sphere mechanism for the hydrogenation; complexation of ZhaoPhos with chloride and DFT calculations indicate that anion binding is an important secondary interaction in catalysis. In the experiment, the researchers used many compounds, for example, 2-Methyl-6-nitro-1H-indole (cas: 3484-23-9Safety of 2-Methyl-6-nitro-1H-indole).
2-Methyl-6-nitro-1H-indole (cas: 3484-23-9) belongs to indole derivatives. In addition to tryptophan, indigo, and indoleacetic acid, numerous compounds obtainable from plant or animal sources contain the indole molecular structure. Moreover, it is known that it controls biofilm formation. However, the role of indole in the cell has not been fully elucidated.Safety of 2-Methyl-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