43191-22-6

Upstream product

• 1603-40-3 3-methylpyridin-2-ylamine 
• 98-80-6 phenylboronic acid 
• 591-50-4 iodobenzene 
• 3430-17-9 2-bromo-3-picoline 
• 62-53-3 aniline 
• 59346-36-0 (3aS,7aS)-7a-Methyl-3-phenyl-3a,7a-dihydro-3H-oxazolo[4,5-b]pyridin-2-one 
• 1003-73-2 3-picoline-N-oxide 
• 103-71-9 phenyl isocyanate 

Downstream Products

• 23275-60-7 4-methylpyrido[1,2-a]benzimidazole 
• 261-00-7 benzo<1,8>naphthyridine 
• 51269-72-8 N-(3-methylpyridin-2-yl)-N-phenylbenzamide 
• 24391-96-6 1,2-diphenyl-1H-pyrrolo[2,3-b]pyridine 
• 1416253-50-3 N-([1,1'-biphenyl]-2-yl)-3-methylpyridin-2-amine 
• 1416253-52-5 C₂₄H₂₀N₂ 
• 1256380-96-7 C₂₆H₂₀N₂ 
• 81416-36-6 3-methyl-2-(N-phenylcarbamoylanilino)pyridine 

Relevant academic research and scientific papers

Tunable Electrochemical C?N versus N?N Bond Formation of Nitrogen-Centered Radicals Enabled by Dehydrogenative Dearomatization: Biological Applications

Herein, an environmentally friendly electrochemical approach is reported that takes advantage of the captodative effect and delocalization effect to generate nitrogen-centered radicals (NCRs). By changing the reaction parameters of the electrode material and feedstock solubility, dearomatization enabled a selective dehydrogenative C?N versus N?N bond formation reaction. Hence, pyrido[1,2-a]benzimidazole and tetraarylhydrazine frameworks were prepared through a sustainable transition-metal- and exogenous oxidant-free strategy with broad generality. Bioactivity assays demonstrated that pyrido[1,2-a]benzimidazoles displayed antimicrobial activity and cytotoxicity against human cancer cells. Compound 21 exhibited good photochemical properties with a large Stokes shift (approximately 130 nm) and was successfully applied to subcellular imaging. A preliminary mechanism investigation and density functional theory (DFT) calculations revealed the possible reaction pathway.

Transition-Metal-Free Synthesis of 1,2-Disubstituted Indoles

Herein, we report a new transition-metal-free robust and cost-effective method for synthesis of 1,2-disubstituted indoles from easily available unactivated (i.e. without EWG, PPh3 or SiR3 groups) tertiary amides. Scope of synthetic applicability of the presented protocol was shown on 23 examples of 1,2-disubstituted indoles with different substitution patterns obtained in good to excellent yields. The reported method turned out to be especially effective for synthesis of N-arylated 2-CF3-indoles. Moreover, this approach can be performed in a one-pot two-step manner directly from commercially available secondary amines. Mechanistic studies showed that acyl transfer might be an important step in the course of the reaction. Viability of the presented approach for benzofurans and benzothiophenes synthesis was also discussed.

Palladium(II)-catalyzed direct ortho arylation of 4-methyl-N-phenylpyridin- 2-amines via C-H activation/C-C coupling and synthetic applications

The direct ortho arylation of 4-methyl-N-phenylpyridin-2-amines via palladium(II)-catalyzed C-H activation is described. Treatment of 4-methyl-N-phenylpyridin-2-amine with potassium aryltrifluoroborate using 10 mol % of palladium(II) acetate as the catalyst, 2 equiv of copper(II) acetate as the oxidant, and 1 equiv of p-benzoquinone in tert-butyl alcohol gave ortho-arylated products in modest to excellent yields. This reaction shows good functional group compatibility. A series of 1H NMR titration experiments and controlled experiments elucidating the reaction mechanism were carried out. The key intermediate, 4-methyl-N-phenylpyridin-2-amine palladacycle, was isolated and characterized by X-ray crystallography. The advanced transformations of ortho-phenylated 4-methyl-N-phenylpyridin-2-amine to N-(4-methylpyridin-2-yl)-9H-carbazole, biphenyl-2-amine, and 3-methyl-6-phenylpyrido[1,2-a]benzimidazole were successfully demonstrated as potential synthetic applications.

C-H cycloamination of N-aryl-2-aminopyridines and N-arylamidines catalyzed by an in situ generated hypervalent iodine(iii) reagent

A metal-free synthesis of diversified pyrido[1,2-a]benzimidazoles and 1H-benzo[d]imidazoles from N-aryl-2-aminopyridines and N-arylamidines has been developed. The C-H cycloamination reaction was catalyzed by hypervalent iodine(iii) species generated in situ from iodobenzene (catalytic) and peracetic acid (stoichiometric). The reaction proceeded smoothly at ambient temperature to provide the corresponding N-heterocycles in good to excellent yields.

A direct intramolecular C-H amination reaction cocatalyzed by copper(II) and iron(III) as part of an efficient route for the synthesis of pyrido[1,2-a ]benzimidazoles from N-aryl-2-aminopyridines

A novel and efficient synthesis of pyrido[1,2-a]benzimidazoles through direct intramolecular aromatic C-H amination of N-aryl-2-aminopyridines has been developed. The reaction, cocatalyzed by Cu(OAc)2 and Fe(NO 3)3?9H

Rh(III)-catalyzed oxidative coupling of N -aryl-2-aminopyridine with alkynes and alkenes

[RhCp*Cl2]2 (1-2 mol %) can catalyze the oxidative coupling of N-aryl-2-aminopyridines with alkynes and arylates to give N-(2-pyridyl)indoles and N-(2-pyridyl)quinolones, respectively, using Cu(OAc)2 as an oxidant. Coupling with styrenes gave mono- and/or disubstituted olefination products.

Reaction of Aromatic N-Oxides with Dipolarophiles. X. Role of Charge-Transfer Complexes in 1,3-Dipolar Cycloaddition of Pyridine N-Oxides to Phenyl Isocyanate

In the 1,3-dipolar cycloaddition reaction of 3-methylpyridine N-oxide with phenyl isocyanate, spectroscopic evidence indicates that phenyl isocyanate forms charge transfer complexes with both pyridine N-oxide and aromatic solvents such as pyridine.In connection with the charge-transfer complex formation, the solvent effect on the site selectivity was investigated.The most prominent solvent effect was observed in the reaction using 3-methylpyridine as a solvent.The equilibrium constants for the interaction of 3-methylpyridine N-oxide with phenyl isocyanate in several solvents were found to be quite large, indicating that the reaction mixtures favor complex formation.The proton nuclear magnetic resonance (1H-NMR) spectra of the mixtures show a high field shift of the methyl signal of 3-methylpyridine N-oxide due to charge-transfer complexation.Based on these results, the structure and role of the complexes are discussed.Keywords - charge-transfer complex; 1,3-dipolar cycloaddition; pyridine N-oxide; phenyl isocyanate; site selectivity; visible absorption spectra; equilibrium constant; frontier molecular orbital; kinetics

Reaction of Aromatic N-Oxides with Dipolarophiles. VI. Further Studies on the 1,3-Dipolar Cycloaddition Reaction of Pyridine N-Oxides with Phenyl Isocyanates

To provide additional evidence for the concerted mechanism postulated for the 1,3-dipolar cycloaddition reaction of pyridine N-oxides with phenyl isocyanates, kinetic studies on the cycloaddition reactions were conducted in a variety of solvents.The cycloaddition showed low sensitivity to the ionizing power of the medium, indicating that it proceeds by a mechanism which involves very little change in charge separation between the ground state and the transition state.The observed cycloadditivity and site selectivity are discussed in terms of the following controlling factors based on MINDO/3 calculations: HOMO-LUMO control, secondary orbital interaction, steric interaction, dipole-dipole interaction and charge-transfer complexation. Keywords - 1,3-dipolar cycloaddition; pyridine N-oxide; phenyl isocyanate; kinetics; frontier molecular orbital; solvent effect