98481-96-0Relevant academic research and scientific papers
3-Aminoindole Synthesis from 2-Nitrochalcones and Ammonia or Primary Amines
Zhang, Guan,Lin, Lu,Yang, Kai,Wang, Shihui,Feng, Qiang,Zhu, Jun,Song, Qiuling
, p. 3718 - 3722 (2019)
A step-economic strategy for 3-aminoindoles synthesis with ammonia or primary amines as “N” source under transition-metal-free conditions was achieved. A series of 3-aminoindoles was obtained with abundant “N” source featuring high efficiency, mild condit
Organic Syntheses via Transition Metal Complexes, 15 - 4-Amino-2-aroylindoles, 2-Alkylideneindolenines, Pyrazino-diindoles, and Azetidines via Template Condensation of Aryl Isocyanides with Carbene Complexes
Aumann, Rudolf,Heinen, Heinrich
, p. 2289 - 2307 (2007/10/02)
Via template condensation of aryl isocyanides Ar-NC (1) (Ar = C6H5, p-MeC6H4, p-NO2C6H4, p-CH3OC6H4, o-CH3OC6H4) with carbene complexes (CO)5M=C(OC2H5)R (2) (M = Cr, Mo; R = C6H5, 2-thienyl, CH3) the 3-amino-2-aroyl (or acyl)indoles 10, 2-alkylideneindolenines 16, pyrazino-diindoles 18, and azetidines 13 are obtained depending on the substituents at the aryl group.Electron-rich aryl isocyanides favour the formation of indoles, electron-poor aryl isocyanides the formation of azetidines.The former react with 2 in the presence of water to give good yields of 10, the latter in the presence of ethanol mainly to yield an open-chain imidic ester 11 together with an azetidine 13.In aprotic solvents 13 is the nain product. 13 forms a mixture of rapidly equilibrating cis/trans-isomers via a rotation of the exo-C=C bond (ΔG% = 57.4 KJ/mol).Hydrolysis of 13 yields an open-chain amide 20, which has a C4-backbone finally built up of three isocyanide carbons and one carbene carbon.In absence of protic nucleophiles, the reaction of electron-rich aryl isocyanides with 2 gives pyrazino-diindoles 18 via the dimerisation of an intermediate 2-alkylideneindole 16.The 7-OCH3 derivative 16e has been obtained in monomeric form since dimerisation is hindered in this case for steric reasons.All reactions described in this paper proceed via intermediate formation of ketenimine complexes 3, to which isocyanides are attached at the central carbon atom of the NCC unit.
