51206-87-2

Upstream product

• 603-76-9 1-methylindole 
• 1038997-90-8 (4-nitrophenyl)(2,4,6-triisopropylphenyl)iodonium triflate 
• 32387-21-6 1-methyl-3-indolecarboxylic acid 
• 586-78-7 para-nitrophenyl bromide 
• 78501-03-8 2-(methyl(phenyl)amino)-1-(4-nitrophenyl)ethan-1-one 
• 636-98-6 p-nitrobenzene iodide 
• 120-72-9 indole 
• 100-01-6 4-nitro-aniline 

Relevant academic research and scientific papers

Catalytic Au(i)/Au(iii) arylation with the hemilabile MeDalphos ligand: Unusual selectivity for electron-rich iodoarenes and efficient application to indoles

The ability of the hemilabile (P,N) MeDalphos ligand to trigger oxidative addition of iodoarenes to gold has been thoroughly studied. Competition experiments and Hammett correlations substantiate a clear preference of gold for electron-enriched substrates both in stoichiometric oxidative addition reactions and in catalytic C-C cross-coupling with 1,3,5-trimethoxybenzene. This feature markedly contrasts with the higher reactivity of electron-deprived substrates typically encountered with palladium. Based on DFT calculations and detailed analysis of the key transition states (using NBO, CDA and ETS-NOCV methods in particular), the different behavior of the two metals is proposed to result from inverse electron flow between the substrate and metal. Indeed, oxidative addition of iodobenzene is associated with a charge transfer from the substrate to the metal at the transition state for gold, but opposite for palladium. The higher electrophilicity of the gold center favors electron-rich substrates while important back-donation from palladium favors electron-poor substrates. Facile oxidative addition of iodoarenes combined with the propensity of gold(iii) complexes to readily react with electron-rich (hetero)arenes prompted us to apply the (MeDalphos)AuCl complex in the catalytic arylation of indoles, a challenging but very important transformation. The gold complex proved to be very efficient, general and robust. It displays complete regioselectivity for C3 arylation, it tolerates a variety of functional groups at both the iodoarene and indole partners (NO2, CO2Me, Br, OTf, Bpin, OMe?) and it proceeds under mild conditions (75 °C, 2 h).

Ascorbic Acid as an Aryl Radical Inducer in the Gold-Mediated Arylation of Indoles with Aryldiazonium Chlorides

In recent years interest in the development of protocols that facilitate the oxidative addition of gold to access mild cross-coupling processes mediated by this metal has increased. In this context, we report herein that ascorbic acid, a natural and readily accessible antioxidant, can be used to accelerate the oxidative addition of aryldiazonium chlorides onto AuI. The aryl–AuIII species generated in this way, has been used to prepare 3-arylindoles in a one-pot protocol starting from anilines and para-, meta-, and ortho- substituted aryldiazonium chlorides. The mechanism underlying the oxidative addition has been examined in detail based on EPR analyses, cyclic voltammetry, and DFT calculations. Interestingly, we have found that in this protocol, the chloride atom induces the AuII/AuIII oxidation step.

HFIP-promoted Bischler indole synthesis under microwave irradiation

1,1,1,3,3,3-Hexafluoropropan-2-ol (HFIP) was found to be effective for the Bischler indole synthesis under microwave irradiation in the absence of a metal catalyst. Under the catalysis of HFIP, a wide range of α-amino arylacetones were successfully transf

Abnormal NHC supported palladacycles: Regioselective arylation of heteroarenes via decarboxylation

We report synthesis of two new palladium(II) complexes of abnormal N-heterocyclic carbene ligands. The catalytic activity of these palladium(II) complexes was examined for the decarboxylative arylation of N-methylindole-carboxylic acids. An exclusive regioselectivity and very good yields were obtained with a variety of aryl halide partners.

AgONO-Assisted Direct C-H Arylation of Heteroarenes with Anilines

A novel copper-catalyzed C-H arylation of heteroarenes with anilines by an in situ diazonium reaction is established by using silver nitrite (AgONO) as an unconventional nitrosating reagent under acid-free conditions. It provides a complementary approach for the C-H arylation of electron-rich heteroarenes with aromatic amines affording a variety of heterobiaryls in moderate to good yields.

Cu(II)-catalyzed direct and site-selective arylation of indoles under mild conditions

We have developed a new site-selective Cu(II)-catalyzed C-H bond functionalization process that can selectively arylate indoles at either the C3 or C2 position under mild conditions. The scope of the arylation process is broad and tolerates broad functionality on both the indole and aryl unit, which makes it amenable to further elaboration. The mechanism of the arylation reaction is proposed to proceed via a Cu(III)-aryl species that undergoes initial electrophilic addition at the C3 position of the indole motif. We speculate that site of indole arylation arises through a migration of the Cu(III)-aryl group from C3 to C2, and this can be controlled by the nature of the group on the nitrogen atom; free (NH)- and N-alkylindoles deliver the C3-arylated product, whereas N-acetylindoles afford the C2 isomer, both with excellent yield and selectivity. Copyright