251933-26-3

Upstream product

• 14508-49-7 2-chloropyrazin 
• 5720-06-9 2-Methoxyphenylboronic acid 
• 27993-70-0 2-(2-methoxyphenyl)-2-oxoacetaldehyde 
• 107-15-3 ethylenediamine 
• 767-91-9 1-ethynyl-2-methoxybenzene 
• 612-15-7 o-methoxystyrene 
• 32111-21-0 2-iodopyrazine 
• 290-37-9 1,4-pyrazine 
• 529-28-2 4-iodoanisol 
• 30882-41-8 pyrazine hydrochloride 
• 492-95-5 2-methoxyphenyldiazonium tetrafluoroborate 
• 578-57-4 2-bromoanisole 
• 16750-63-3 2-methoxyphenylmagnesium bromide 

Downstream Products

• 570432-60-9 2-(pyrazin-2-yl)phenol 

Relevant academic research and scientific papers

Direct C-H photoarylation of diazines using aryldiazonium salts and visible-light

In this study, direct C-H photoarylation of pyrazine with aryldiazonium salts under visible-light irradiation (blue-LEDs) is described, and additional examples including photoarylations of pyrimidine and pyridazine are also covered. The corresponding aryl-diazines were prepared in yields up to 84% only by mixing and irradiating the reaction with no need for an additional photocatalyst. We demonstrate the efficacy of this protocol by the scope with electron-donor, -neutral, and -withdrawing groups attached at the ortho, meta, and para positions of the aryldiazonium salts; the results are better than those reported for ruthenium-complex mediated photoarylations. Additionally, we demonstrate the robustness of this methodology with a 5 mmol scaled-up experiment. Mechanistic studies were carried out giving support to the proposal of a photocatalyzed approach by an electron donor-acceptor (EDA) complex, also highlighting the crucial role that solvents play in the formation of the EDA complex. This journal is

NaH-mediated direct C-H arylation in the presence of 1,10-phenanthroline

Transition-metal-free coupling of haloarenes with unactivated arenes has been developed in the presence of NaH and 1,10-phenanthroline. Various haloarenes bearing methyl, methoxy, halogen (fluoride, chloride, and bromide), cyano, trifluoromethyl, ester, and amide groups can be cross-coupled with unactivated arenes, or heteroarenes in this reaction.

Synthesis of Chemically and Configurationally Stable Monofluoro Acylboronates: Effect of Ligand Structure on their Formation, Properties, and Reactivities

The recent disclosures of two classes of acylborons, potassium acyltrifluoroborates (KATs) and N-methyliminodiacetyl (MIDA) acylboronates, demonstrated that certain acylboron species can be both remarkably stable and uniquely reactive. Here we report new classes of ligands for acylboronates that have a significant influence on the formation, properties, and reactivities of acylboronates. Our systematic investigations identified a class of neutral, monofluoroboronates that can be prepared in a one step, gram-scale fashion from readily accessible KATs. These monofluoroboronates are stable to air, moisture, and silica gel chromatography and can be easily handled without any special precautions. X-ray crystallography, NMR spectroscopy, and HPLC studies showed that they are tetravalent, configurationally stable B-chiral acylboronates. Significantly, the ligands on the boronate allow for fine-tuning of the properties and reactivity of acylboronates. In amide-forming ligation with hydroxylamines under aqueous conditions, a considerable difference in reactivity was observed as a function of ligand structure. The solid-state structures suggested that subtle steric and conformational factors modulate the reactivities of the acylboronates.

Can Palladium Acetate Lose Its "saltiness"? Catalytic Activities of the Impurities in Palladium Acetate

Commercially available palladium acetate often contains two major impurities, whose presence can impact the overall catalytic efficacy. This systematic study provides a comparison of the differences in catalytic activity of pure palladium acetate, Pd3(OAc)6, with the two impurities: Pd3(OAc)5(NO2) and polymeric [Pd(OAc)2]n in a variety of cross-coupling reactions. The solid state 13C NMR spectra of all three compounds in conjunction with DFT calculations confirm their reported geometries.

Copper-catalysed cross-coupling of arylzirconium reagents with aryl and heteroaryl iodides

An unprecedented CuI-catalysed cross-coupling of arylzirconium reagents with aryl and heteroaryl iodides is reported. Mechanistic studies with a Cp2ZrAr2 complex revealed that Cp2Zr(Ar)(Cl) is the reactive species that undergoes transmetalation with (PN-1)CuI. In addition, experiments with radical probes indicated that the reaction proceeds via a non-radical pathway. This journal is

Iodine-mediated oxidative annulation for one-pot synthesis of pyrazines and quinoxalines using a multipathway coupled domino strategy

An efficient iodine-mediated oxidative annulation of aryl acetylenes-arylethenes-aromatic ketones with 1,2-diamines for the synthesis of pyrazines and regioselective synthesis of quinoxalines is presented. A multipathway coupled domino approach has been developed for the one-pot synthesis of 1,4-diazines with high functional group compatibility.

A general catalyst for Suzuki-Miyaura and Sonogashira reactions of aryl and heteroaryl chlorides in water

We report the synthesis of 2-(3-sulfonatomesityl)-5-sulfonatoindenyl) dicyclohexylphosphine hydrate sodium salt and its use in palladium-catalyzed Suzuki-Miyaura and Sonogashira coupling reactions in water (and biphasic water-organic solvent mixtures) to prepare a variety of functionalized biaryls and aryl alkynes in excellent yield. This journal is the Partner Organisations 2014.

Gold(I)-catalyzed direct C-H arylation of pyrazine and pyridine with aryl bromides

An efficient procedure for the direct C-H arylation of electron-poor aromatics such as pyrazine and pyridine with aryl bomides is described. In the presence of catalytic amount of Cy3PAuCl and with the use of t-BuOK as base, pyrazine undergoes the direct C-H arylation with aryl bromides at 100 °C, and the yields of the arylated products depend on the nature of aryl bromides. In the cases of electron-rich aryl bromides used, the arylated pyrazines can be obtained in good to high yields. For electron-poor aryl bromides, the addition of AgBF4 is the crucial point to accelerate the coupling reaction to give the arylated products in moderate yields. Pyridine also reacts with electron-rich aryl bromides catalyzed by Cy3PAuCl to give a mixture of arylated regioisomers in moderate yield. However, in order to realize the direct C-H arylation of pyridine with electron-poor aryl bromides, the addition of silver salt as additive and a milder reaction temperature (60 °C) are required.

Aryl-aryl bonds formation in pyridine and diazine series. Diazines part 41

The synthesis of several symmetrical polyaromatic compounds with pyridine or diazine units has been achieved by homocoupling of aryl halides with Pd(OAc)2 as catalyst. Cross-coupling reactions of aryl Grignard reagents with Fe(acac)3 as catalyst allowed the synthesis of various unsymmetrical polyaryl- or polyheteroaryl compounds with π-deficient rings.

α1-Adrenoceptor agonists: The identification of novel α1A subtype selective 2′-heteroaryl-2-(phenoxymethyl)imidazolines

Novel 2′-heteroaryl-2-(phenoxymethyl)imidazolines have been identified as potent agonists of the cloned human α1-adrenoceptors in vitro. The nature of the 2′-heteroaryl group can have significant effects on the potency, efficacy, and subtype selectivity in this series. α1A Subtype selective agonists have been identified.