26490-74-4

Upstream product

• 120-72-9 indole 
• 1074-12-0 phenylglyoxal hydrate 
• 1075-06-5 2,2-dihydroxy-1-phenyl-ethanone 
• 98-86-2 acetophenone 

Downstream Products

• 38693-01-5 2-hydroxy-1-(1H-indol-3-yl)-2-phenyl-ethanone 
• 1316302-66-5 1-(4-(1H-indol-3-yl)-2-methyl-5-phenylfuran-3-yl)ethanone 

Relevant academic research and scientific papers

Gold-Catalyzed Reactions of 2-Alkynyl-1-indolyl-1,2-diols with Thiols: Stereoselective Synthesis of (Z)-α-Indol-3-yl α-(2-Thioalkenyl) Ketones

Propargylic glycols, 2-alkynyl-1-(indol-3-yl)-1,2-diols, react with thiols undergoing a complex but selective gold-catalyzed transformation that gives rise to α-indol-3-yl α-((Z)-2-thioalkenyl) ketones. The sequence is triggered by the regioselective thiolation of indolyl diols followed by an attack of the sulfur instead of the indole over the activated alkyne. The final compounds are obtained in remarkably high yields and arise from simple starting materials such as indolyl acyloins, ethynyl magnesium bromide and thiols. (Figure presented.).

An organocatalytic asymmetric Friedel-Crafts reaction of 2-substituted indoles with aldehydes: enantioselective synthesis of α-hydroxyl ketones by low loading of chiral phosphoric acid

Hydroxyl alkylation of indoles by Friedel-Crafts reaction with a carbonyl compound is a useful strategy. However, the reaction was restricted to ketones due to the easy formation of a bisindole byproduct. Therefore, hydroxyl alkylation of an aldehyde with indole is confronted with great challenges. Here, we report an efficient strategy for asymmetric hydroxyl alkylation of 2-substituted indoles with aldehydes under 0.1 mol% chiral phosphoric acid. A series of α-hydroxyl ketones were obtained in high yields (up to 99%) and good enantioselectivities (up to 97%).

Synthesis of α-functionalized α-indol-3-yl carbonyls through direct SN reactions of indol-3-yl α-acyloins

A new and efficient synthesis of α-functionalized α-indol-3-yl ketones from easily available indolyl α-acyloins is reported. This process, catalyzed by Br?nsted or Lewis acids, involves an uncommon direct nucleophilic substitution reaction of a secondary α-carbonyl-substituted hydroxyl group. The described methodology allows the introduction of a variety of nucleophiles such as (hetero)arenes, thiophenols, nitroanilines and 1,3-dicarbonyl derivatives. The synthesized α-indol-3-yl carbonyl compounds are important synthetic targets also useful for accessing functionalized tryptophols and furan-3-yl indoles.

Aminocatalytic cross-coupling approach via iminium ions to different C-C bonds

Given the attractive ability of iminium ions to functionalize molecules directly at ostensibly unreactive positions, the reactivity of iminium ions, in which an α CH2 group is replaced by C=O was explored. Background studies on the ability of such iminium cations to promote reactions via an iminium-catalyzed or iminium-equivalent pathway are apparently unavailable. Previously, tandem cross-coupling reactions were reported, in which an iminium ion undergoes nucleophilic 1,2-addition to give a putative three-component intermediate that abstracts a proton in situ and undergoes self-deamination followed by unprecedented DMSO/ aerobic oxidation to generate a-ketoamides. However, later it was observed that iminium ions can generate valuable α-ketoamides through simple aerobic oxidation. In all reactions, iminium ions were generated in situ by reaction of 2-oxoaldehydes with secondary amines.

Reaction of arylglyoxals with pyrrole or indole in aqueous media: Facile synthesis of heteroaryl α-acyloins

Pyrrole or indole reacts with arylglyoxal monohydrates in aqueous media in the absence of any catalyst to produce pyrrol-2-yl or indol-3-yl α-acyloin derivatives in high yields as the only product. Reactions were clean and products were isolated by simple filtration. When the reactions were carried out in acetonitrile as solvent, different products were obtained.

Reaction of Arylglyoxals with Electron-Rich Benzenes and π-Excessive Heterocycles. Facile Synthesis of Heteroaryl α-Acyloins

The reaction of arylglyoxals and their hydrates with electron-rich benzenes and π-excessive heterocycles, if conducted in the absence of catalysts, affords α-benzoins.