1201938-06-8

Upstream product

• 3682-71-1 2-phenyl-2H-indazole 
• 673-40-5 4-bromobenzenediazonium tetrafluoroborate 
• 106-40-1 4-bromo-aniline 
• 1122-91-4 4-bromo-benzaldehyde 
• 17082-12-1 trans-azobenzene 
• 1456728-72-5 C₁₉H₁₃BrN₂O₂ 
• 7099-87-8 4-bromophenylglyoxylic acid 
• 495-48-7 azoxybenzene 
• 62-53-3 aniline 
• 1227476-15-4 Azobenzene 
• 1421276-18-7 C₁₉H₁₃BrN₂O 
• 589-87-7 1,4-bromoiodobenzene 

Relevant academic research and scientific papers

Metal-free, regioselective, visible light activation of 4CzIPN for the arylation of 2H-indazole derivatives

Highly regioselective organo photocatalysis of 4CzIPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene) for the arylation of 2H-indazole is demonstrated. The present synthetic route provides a highly safe and easily accessible aniline precursor as an arylation reagent. The photoactivated 4CzIPN organocatalyst is found to be more efficient for single electron transfer without any organic base for the radical reaction. The carbazole-based photocatalyst (4CzIPN) with wide redox potential is stable and recyclable for further reaction transformations. Many indazole and aniline derivatives were used in the reaction and provided the arylated indazole derivatives in good to excellent yield.

Visible-light-mediated direct C3-arylation of 2: H -indazoles enabled by an electron-donor-acceptor complex

A mild visible-light-mediated, photocatalyst-free arylation of 2H-indazoles was developed. The formation of an electron donor-acceptor complex by 2H-indazoles and aryl diazonium salts in the presence of pyridine allows the direct arylation of 2H-indazoles under visible-light irradiation. This process provides an efficient route for the synthesis of C3-arylated-2H-indazoles, which are important scaffolds of various bioactive compounds.

Continuous-Flow Visible Light Organophotocatalysis for Direct Arylation of 2H-Indazoles: Fast Access to Drug Molecules

A continuous-flow homogeneous photocatalytic method has been devised for the direct arylation of 2H-indazoles. This visible-light-promoted approach directly accesses a wide range of structurally diverse C3-arylated scaffolds of biological interest in a fa

Rhenium-Catalyzed [4 + 1] Annulation of Azobenzenes and Aldehydes via Isolable Cyclic Rhenium(I) Complexes

The first Re-catalyzed [4 + 1] annulation of azobenzenes with aldehydes was developed to furnish 2H-indazoles via isolable and characterized cyclic ReI-complexes. For the first time, the acetate-acceleration effect is showcased in Re-catalyzed C-H activation reactions. Remarkably, mechanistic studies revealed an irreversible aldehyde-insertion step, which is in sharp contrast to those of previous Rh- and Co-systems. (Chemical Presented).

Cobalt(III)-catalyzed synthesis of indazoles and furans by C-H bond functionalization/addition/cyclization cascades

The development of operationally straightforward and cost-effective routes for the assembly of heterocycles from simple inputs is important for many scientific endeavors, including pharmaceutical, agrochemical, and materials research. In this article we describe the development of a new air-stable cationic Co(III) catalyst for convergent, one-step benchtop syntheses of N-aryl-2H-indazoles and furans by C-H bond additions to aldehydes followed by in situ cyclization and aromatization. Only a substoichiometric amount of AcOH is required as an additive that is both low-cost and convenient to handle. The syntheses of these heterocycles are the first examples of Co(III)-catalyzed additions to aldehydes, and reactions are demonstrated for a variety of aromatic, heteroaromatic, and aliphatic derivatives. The syntheses of both N-aryl-2H-indazoles and furans have been performed on 20 mmol scales and should be readily applicable to larger scales. The reported heterocycle syntheses also demonstrate the use of directing groups that have not previously been applied to Co(III)-catalyzed C-H bond functionalizations. Additionally, the synthesis of furans demonstrates the first example of Co(III)-catalyzed functionalization of alkenyl C-H bonds.

Unprecedented ortho-acylation of azoxybenzenes with α-oxocarboxylic acids by Pd-catalyzed C-H activation and decarboxylation

A palladium-catalyzed ortho-acylation reaction of azoxybenzenes with α-oxocarboxylic acids was developed in the presence of K2S 2O8. The established methodology provides a direct approach to obtain acylated azoxybenzenes in good yields.

Direct access to acylated azobenzenes via Pd-catalyzed C-H functionalization and further transformation into an indazole backbone

Azobenzenes were readily acylated at the 2-position through a Pd-catalyzed C-H functionalization from simple aromatic azo compounds and aldehydes in good yields. The obtained acylated azobenzenes could be efficiently converted into the corresponding indaz

Direct arylations of 2H-Lndazoles on water

(Figure presented) The efficient palladium-catalyzed synthesis of a range of substituted 2H-lndazoles via C-H arylation Is reported. Reactions are performed on water and provide a direct and mild route toward 2,3-diaryl Indazoles of widespread biological significance.