537684-23-4

Upstream product

• 120-72-9 indole 
• 615-37-2 ortho-methylphenyl iodide 
• 16419-60-6 2-Methylphenylboronic acid 
• 95-49-8 2-methylchlorobenzene 
• 95-46-5 2-methylphenyl bromide 
• 1885-29-6 anthranilic acid nitrile 
• 36804-45-2 (2-aminophenyl)(2-methylphenyl)methanone 
• 529-27-1 2-methylphenylhydrazine 
• 99655-68-2 3-bromo-1-phenylsulfonyl indole 
• 40899-71-6 1-benzenesulfonylindole 
• 883141-48-8 3-(2-methylphenyl)-1-(phenylsulfonyl)-1H-indole 

Downstream Products

• 883141-51-3 1-methyl-3-(2-methylphenyl)-1H-indole 

Relevant academic research and scientific papers

Pd/β-cyclodextrin-catalyzed C-H functionalization in water: A greener approach to regioselective arylation of (NH)-indoles with aryl bromides

A greener and more practical strategy for the site-selective C-H arylation of (NH)-indoles via coupling of (hetero)aryl bromides was developed, in which β-cyclodextrin, acting as both a ligand for Na2PdCl4 and a host for indoles, enables the reactions to occur easily in water. The key advantage of this method is the ingenious merging of aqueous homogeneous catalysis and ligand mediation, leading to the highly regioselective formation of C3-arylindoles with a broad substrate scope and functional-group tolerance. Moreover, the regioselectivity can be switched from the C3 to the C2-position by varying the nature of the base without recourse to employing ArI as substrates.

Regiospecificity in Ligand-Free Pd-Catalyzed C-H Arylation of Indoles: LiHMDS as Base and Transient Directing Group

A highly efficient catalyst-base pair for the C-H arylation of free (NH)-indoles in the C-3 position is reported. Ligand-free palladium acetate coupled with lithium hexamethyldisilazide (LiHMDS) catalyzed the regiospecific, i.e. 100% regioselective, C-3 a

Iron-Promoted Construction of Indoles via Intramolecular Oxidative C-N Coupling of 2-Alkenylanilines Using Persulfate

Indole scaffold synthesis relies primarily on oxidative C-H amination of N-protected alkenylanilines for C-N intramolecular cyclization reactions. Herein, for the first time, without N-protection, various readily prepared 2-alkenylanilines were transformed into the desired indole products in good yields by using K 2 S 2 O 8 as oxidant in the presence of catalytic amounts of FeF 2. The K 2 S 2 O 8 /FeF 2 system offers a direct and benign synthetic route to 3-arylindoles and it is applicable to a wide range of substituted indoles including drug intermediates.

Palladium-catalyzed direct C3-selective arylation of n-unsubstituted indoles with aryl chlorides and triflates

The direct C3-arylation of N-unsubstituted indoles with aryl chlorides and triflates has been realized using a palladium-dihydroxyterphenylphosphine (DHTP) catalyst. The site selectivity is different from that obtained with other structurally related ligands. This unique feature of the DHTP ligand is attributed to complex formation between the lithium salts of the ligand and the indole. The method was applied to the late-stage derivatization of pharmaceuticals having a chloro group.

Pyridylmethylamine–Palladium Catalytic Systems: A Selective Alternative in the C?H Arylation of Indole

A highly efficient pyridylmethylamine-Pd alternative catalytic system for the C?H arylation of indole was explored. Variously substituted aryl groups were regio- and chemoselectively installed at the indole nucleus by using barium hydroxide as the base. The method was found to be efficient even in the presence of hindered coupling partners and Pd-reactive bonds.

Palladium-catalyzed direct denitrogenative C-3-arylation of 1H-indoles with arylhydrazines using air as the oxidant

A novel palladium-catalyzed approach to direct C-3-arylation of 1H-indoles with arylhydrazines using air as the oxidant via C-N bond cleavage has been developed. Various substituents are tolerated in this system in moderate to good yields. This reaction could also be compatible with a larger scale. Thus, this strategy using arylhydrazines as arylating reagents provides a powerful method for constructing substituted 3-aryl-1H-indoles. Copyright

The synthesis of 2- and 3-aryl indoles and 1,3,4,5-tetrahydropyrano[4,3-b]indoles and their antibacterial and antifungal activity

A series of 2- and 3-aryl substituted indoles and two 1,3,4,5-tetrahydropyrano[4,3-b]indoles were synthesized from indole and 5-methoxyindole. The 2-aryl indoles were synthesized from the 1-(phenylsulfonyl)indole derivatives using magnesiation followed by iodination. The 2-iodinated compounds were then subjected to Suzuki-Miyaura reactions. In addition, the 3-aryl indoles were made from the corresponding 3-bromoindoles using Suzuki-Miyaura reactions. The 1,3,4,5-tetrahydropyrano[4,3-b]indoles were also synthesized from 1-(phenylsulfonyl)indole by magnesiation followed by treatment with allylbromide. The product was then converted into [2-allyl-1-(phenylsulfonyl)-1H-indol-3-yl]methanol which upon exposure to Hg(OAc)2 and NaBH4 afforded tetrahydropyrano[4,3-b]indoles. A number of the 2- and 3-aryl indoles displayed noteworthy antimicrobial activity, with compound 13a displaying the most significant activity (3.9 μg/mL) against the Gram-positive micro-organism Bacillus cereus.

Direct palladium-catalyzed C-3 arylation of free (NH)-indoles with aryl bromides under ligandless conditions

(Chemical Equation Presented) A new method for the efficient, practical, and highly regioselective direct palladium-catalyzed C-3 arylation of free (NH)-indole and its electron-rich 1-unsubstituted derivatives under ligandless conditions is described. The reactions, which are run outside a glovebox without purification of solvent and reagents, involve treatment of free (NH)-indoles with activated, unactivated, and deactivated aryl bromides in refluxing toluene in the presence of K2CO3 as the base and a catalyst system consisting of a combination of Pd(OAc)2 and benzyl(tributyl)ammonium chloride. The experimental results are consistent with a catalytic cycle based on an electrophilic palladation pathway at the 3-position of 1-indolyl potassium salts.

A concise synthesis of novel naphtho[a]carbazoles and benzo[c]carbazoles

Starting from simple indole precursors the synthesis of naphtho[a]carbazoles and benzo[c]carbazoles is described. Key steps include the use of the Suzuki-Miyaura reaction to afford 2- or 3-aryl substituted indoles, as well as a potassium t-butoxide and light assisted aromatic ring-forming reaction.

Direct palladium-catalyzed C-2 and C-3 arylation of indoles: A mechanistic rationale for regioselectivity

We have recently developed palladium-catalyzed methods for direct arylation of indoles (and other azoles) wherein high C-2 selectivity was observed for both free (NH)-indole and (NR)-indole. To provide a rationale for the observed selectivity ("nonelectrophilic" regioselectivity), mechanistic studies were conducted, using the phenylation of 1-methylindole as a model system. The reaction order was determined for iodobenzene (zero order), indole (first order), and the catalyst (first order). These kinetic studies, together with the Hammett plot, provided a strong support for the electrophilic palladation pathway. In addition, the kinetic isotope effect (KIEH/D) was determined for both C-2 and C-3 positions. A surprisingly large value of 1.6 was found for the C-3 position where the substitution does not occur (secondary KIE), while a smaller value of 1.2 was found at C-2 (apparent primary KIE). On the basis of these findings, a mechanistic interpretation is presented that features an electrophilic palladation of indole, accompanied by a 1,2-migration of an intermediate palladium species. This paradigm was used to design new catalytic conditions for the C-3 arylation of indole. In case of free (NH)-indole, regioselectivity of the arylation reaction (C-2 versus C-3) was achieved by the choice of magnesium base.