18503-48-5

Usage

Synthesis Reference(s)

Tetrahedron, 46, p. 2525, 1990 DOI: 10.1016/S0040-4020(01)82033-0

Upstream product

• 91-19-0 2,3-diethynylquinoxaline 
• 507-19-7 t-butyl bromide 
• 35448-10-3 oxalic acid mono-tert-butyl ester 
• 98-89-5 Cyclohexanecarboxylic acid 
• 630-19-3 pivalaldehyde 
• 6832-15-1 1-diazo-3,3-dimethyl-2-butanone 
• 95-54-5 1,2-diamino-benzene 
• 59562-82-2 3,3-dimetylbutan-1,2-diol 
• 3282-30-2 pivaloyl chloride 
• 88-74-4 2-nitro-aniline 
• 84379-72-6 1,3-dioxoisoindolin-2-yl 3,3-dimethylbutanoate 
• 84380-38-1 S-tert-butyl O-ethyl carbonodithioate 
• 23269-74-1 1-[1-(phenyl)vinyl]-1H-benzo[d][1,2,3]triazole 
• 142321-29-7 1-(hex-1-en-2-yl)-1H-benzo[d][1,2,3]triazole 

Relevant academic research and scientific papers

An ultrastable olefin-linked covalent organic framework for photocatalytic decarboxylative alkylations under highly acidic conditions

The application of two-dimensional covalent organic frameworks (2D-COFs) as photoredox catalysts offers sustainable alternatives for visible-light-driven organic transformations. However, under highly complicated organic reaction conditions, maintaining their basic structure and photoactivity is always neglected, which impedes their potential in more organic reaction types and industrial use. Herein, we describe a visible-light-driven decarboxylative alkylation of heterocycles catalysed by an olefin-linked covalent organic framework (2D-COF-2) instead of the commonly used precious metal complexes and organic dyes. A wide range of alkylated heterocycles were selectively and efficiently synthesized under heterogeneous reaction conditions. Relying on the ultrastability of olefin linkage, 2D-COF-2 maintained its basic structure and photoactivity under highly acidic conditions. Moreover, its streamlining industrial potential was demonstrated in recycling experiments, functionalization of bioactive molecules and scale-up reactions.

Iron-catalyzed one-pot synthesis of quinoxalines: Transfer hydrogenative condensation of 2-nitroanilines with vicinal diols

Here, we report iron-catalyzed one-pot synthesis of quinoxalines via transfer hydrogenative condensation of 2-nitroanilines with vicinal diols. The tricarbonyl (η4-cyclopentadienone) iron complex, which is well known as the Kn?lker complex, catalyzed the oxidation of alcohols and the reduction of nitroarenes, and the corresponding carbonyl and 1,2-diaminobenzene intermediates were generated in situ. Trimethylamine N-oxide was used to activate the iron complex. Various unsymmetrical and symmetrical vicinal diols were applied for transfer hydrogenation, resulting in quinoxaline derivatives in 49-98% yields. A plausible mechanism was proposed based on a series of control experiments. The major advantages of this protocol are that no external redox reagents or additional base is needed and that water is liberated as the sole byproduct. This journal is

Iridium-Catalyzed [4+2] Annulations of β-Keto Sulfoxonium Ylides and o-Phenylenediamines: Mild and Facile Synthesis of Quinoxaline Derivatives

A synthetic method for quinoxaline derivatives from the [4+2] annulation of β-keto sulfoxonium ylides and o-phenylenediamine by using (Cp*IrCl2)2 catalyst is described. This novel protocol features mild reaction conditions, moderate to excellent yields, wide substrate scope, and high functional-group compatibility. Moreover, this cyclization strategy was successfully applied in late-stage modification for structurally complex bioactive compounds.

Design and implementation of a catalytic electron donor?acceptor complex platform for radical trifluoromethylation and alkylation

Electron donor?acceptor (EDA) complexes can controllably generate radicals under mild conditions through selective photoexcitation events. However, unproductive reactivity from fast deactivation of the photoexcited complexes through back electron transfer has slowed the development of EDA complexes in synthetic methodology. Here, we disclose the study of EDA complexes derived from 2-methoxynaphthalene donor and acylated ethyl isonicotinate N-oxide acceptor that undergo a fast N?O bond fragmentation event upon photoexcitation. This reaction design not only overcomes the limitations of back electron transfer but also enables regeneration of the donor species, representing a rare example of EDA photochemistry in a catalytic regime. The synthetic utility is demonstrated through visible light-driven radical trifluoromethylation and Minisci alkylation reactions. The scalability of the EDA complex-promoted reaction is evidenced by the successful multigram-scale trifluoromethylation of methyl N-Boc pyrrole-2-carboxylate in a continuous flow manifold.

Application of a reusable Co-based nanocatalyst in alcohol dehydrogenative coupling strategy: Synthesis of quinoxaline and imine scaffolds

A nitrogen doped carbon supported cobalt catalyzed efficient synthesis of imines and quinoxaline motifs is reported. Co(OAc)2-Phen/Carbon-800 (Co-phen/C-800) showed the superior reactivity compared to other materials prepared at different temperature, in the synthesis of quinoxalines by the coupling between diamines and diols. Moreover, applying the transfer hydrogenation and acceptorless dehydrogenative coupling strategy, imines and quinoxaline derivatives were synthesized from the nitro compounds. The practical applicability of this protocol was demonstrated by the gram-scale synthesis and the reusability of the catalyst upto 8th cycle. Furthermore, several kinetic experiments were carried out to realize the probable mechanism.

Nickel-Catalyzed Direct Synthesis of Quinoxalines from 2-Nitroanilines and Vicinal Diols: Identifying Nature of the Active Catalyst

The inexpensive and simple NiBr2/1,10-phenanthroline system-catalyzed synthesis of a series of quinoxalines from both 2-nitroanilines and 1,2-diamines is demonstrated. The reusability test for this system was performed up to the seventh cycle, which afforded good yields of the desired product without losing its reactivity significantly. Notably, during the catalytic reaction, the formation of the heterogeneous Ni-particle was observed, which was characterized by PXRD, XPS, and TEM techniques.

Mn(II)-catalyzed C-H alkylation of imidazopyridines and N-heteroarenes via decarbonylative and cross-dehydrogenative coupling

A Mn(II)-catalyzed efficient C-H alkylation of imidazoheterocycles and N-heteroarenes with aliphatic aldehydes has been developed via oxidative decarbonylation. Other alkylating agents such as cyclic alkanes, ethers, and alcohols also coupled with N-heteroarenes through cross-dehydrogenative coupling. Regioselectively C5-alkylated imidazoheterocycles were synthesized in good yields. Experimental results show that radical pathway might be involved in this reaction.

Cooperative iridium complex-catalyzed synthesis of quinoxalines, benzimidazoles and quinazolines in water

Herein, an efficient methodology for the synthesis of a diverse class of N-heterocyclic moieties, such as quinoxalines, benzimidazoles and quinazolines, was developed in water using bio-renewable alcohols. The quinoxalines were successfully synthesized from a wide range of diamines and nitroamines with diols in air. Interestingly, benzimidazoles and quinazolines were synthesized with excellent isolated yields without using any external base. Finally, the preparative scale synthesis of various N-heterocycles and pharmaceutically active quinoxalines established the practicability of this protocol. For this iridium system, a metal-ligand cooperative mechanism was proposed based on kinetic and DFT studies.

Visible Light-Mediated Decarboxylative Alkylation of Pharmaceutically Relevant Heterocycles

A net redox-neutral method for the decarboxylative alkylation of heteroarenes using photoredox catalysis is reported. Additionally, this method features the use of simple, commercially available carboxylic acid derivatives as alkylating agents, enabling the facile alkylation of a variety of biologically relevant heterocyclic scaffolds under mild conditions.

Cobalt complex catalyzed atom-economical synthesis of quinoxaline, quinoline and 2-alkylaminoquinoline derivatives

A new phosphine-free Co(ii) complex-catalyzed synthesis of various quinoxalines via dehydrogenative coupling of vicinal diols with both o-phenylenediamines and 2-nitroanilines is reported. This complex was also effective for the synthesis of quinolines. The practical aspect of this catalytic system was revealed by the one-pot synthesis of 2-alkylaminoquinolines.