1484-28-2

Upstream product

• 83-34-1 3-Methylindole 

Downstream Products

• 1504-06-9 3-methylindolin-2-one 
• 674819-73-9 1-[2-(1-benzyl-3-methyl-1H-indol-2-yl)phenyl]-1-ethanone 
• 674819-72-8 1-benzyl-2-bromo-3-methyl-1H-indole 
• 196713-98-1 tert-butyl 2-bromo-3-methyl-1H-indole-1-carboxylate 

Relevant academic research and scientific papers

Regiospecific bromination of 3-methylindoles with N-bromosuccinimide

The regiospecific bromination of various substituted 3-methylindoles at either C(2) or the C(3) alkyl moiety was accomplished via an electrophilic of free radical bromination process to provide intermediates for indole alkaloid total synthesis. The regiospecificity of the bromination could be controlled by variation of both the substituent and the N(1) protecting group on the indole ring.

Halogenation of indoles with copper(II) halides: Selective synthesis of 2-halo-, 3-halo-, and 2,3-dibromoindoles

A simple and selective protocol for the halogenation of indoles with copper(II) bromide or chloride to synthesize 2-halo-, 3-halo-, and 2,3-dibromoindoles was developed. It was found that both base and water could be used as switches for the selectivity of the halogenation reactions. In the presence of copper(II) halide and sodium hydroxide, 3-haloindoles were obtained as the major products, whereas the selectivity was shifted toward 2,3-dihaloindoles when water was added instead of sodium hydroxide. Moreover, 2-halogenations of 3-substituted indoles were also performed successfully in moderate to good yields under the standard conditions. Georg Thieme Verlag Stuttgart.

Synthetic Routes to Isomeric Imidazoindoles by Regioselective Ring-Opening of Activated Aziridines Followed by Copper-Catalysed C–N Cyclization

Two new synthetic routes that deliver substituted imidazoindoles in high yields with excellent ee values have been developed. The reactions proceed through ring-opening of activated aziridines with 2,2-dibromovinylanilines or 2-bromoindoles, followed by a Cu-catalysed domino C–N,C–N-cyclization, or a C–N cyclization, respectively. The first route gives rise to one regioisomer, and the second route gives the other.

Predicting the Substrate Scope of the Flavin-Dependent Halogenase BrvH

The recently described flavin-dependent halogenase BrvH is able to catalyse both the bromination and chlorination of indole, but shows significantly higher bromination activity. BrvH was annotated as a tryptophan halogenase, but does not accept tryptophan as a substrate. Its native substrate remains unknown. A predictive model with the data available for BrvH was analysed. A training set of compounds tested in vitro was docked into the active site of a complete protein model based on the X-ray structure of BrvH. The atoms not resolved experimentally were modelled by using molecular mechanics force fields to obtain this protein model. Furthermore, docking poses for the substrates and known non-substrates have been calculated. Parameters like distance, partial charge and hybridization state were analysed to derive rules for predicting activity. With this model for activity of the BrvH, a virtual screening suggested several structures for potential substrates. Some of the compounds preselected in this way were tested in vitro, and several could be verified as convertible substrates. Based on information on halogenated natural products, a new dataset was created to specifically search for natural products as substrates/products, and virtual screening in this database yielded further hits.

The synthesis of indolo- and pyrrolo[2,1-a]isoquinolines

The synthesis of fused isoquinolines from N-benzyl protected indoles and pyrroles is described. For example, treatment of t-butyl-2-(2-formyl-3,4- dihydro-1-naphthalenyl)-3-methyl-1H-indole-1-carboxylate with KOBut in DMF provided 14-methyl-8-phenylbenzo[h]indolo[2,1-a]isoquinoline in good yield. Analogous N-benzylpyrrole precursors could similarly be cyclized to give pyrrolo[2,1-a]isoquinolines.

Heteroaryl radicals in synthesis: Radical cyclisation reactions of 2-bromoindoles

The synthesis and radical cyclisations of 2-bromoindoles carrying an unsaturated N-alkyl group is described.

Regiospecific Bromination of 3-Methylindoles with NBS and Its Application to the Concise Synthesis of Optically Active Unusual Tryptophans Present in Marine Cyclic Peptides

A regiospecific bromination of substituted 3-methylindoles at either the C(3) alkyl moiety or the C(2) position was achieved via a free radical bromination or electrophilic process, respectively. The regiospecificity of the bromination could be controlled by variation of both the substituent and the N(1) protecting group on the indole ring. In addition, enantiospecific syntheses of 5-methoxytryptophan (20) and 5-hydroxy-6-chlorotryptophan (21c) as well as concise syntheses of optically active 2-bromotryptophan ethyl esters 26a,b or their substituted derivatives in three steps from bifunctional dibromoindoles were achieved via the above regiospecific process.

A SUPERIOR SYNTHETIC METHOD FOR THE BROMINATION OF INDOLES AND BENZIMIDAZOLES.

Brominated indoles and benzimidazoles are formed in very high yields and with substantial regioselectivity by use of a reagent system consisting of N-bromosuccinimide (NBS) and silica gel in dichloromethane.