61859-84-5

Upstream product

• 1120-90-7 3-iodopyridine 
• 292638-85-8 acrylic acid methyl ester 
• 1126-74-5 3-(pyridin-3-yl)acrylic acid 
• 108-59-8 malonic acid dimethyl ester 
• 626-55-1 3-Bromopyridine 
• 500-22-1 3-pyridinecarboxaldehyde 
• 96-32-2 bromoacetic acid methyl ester 

Downstream Products

• 69963-46-8 3-(pyridin-3-yl)prop-2-en-1-ol 
• 28447-15-6 3-(3-pyridyl)acrolein 

Relevant academic research and scientific papers

Synthesis and Assessment of Novel Probes for Imaging Tau Pathology in Transgenic Mouse and Rat Models

Aggregated tau protein is a core pathology present in several neurodegenerative diseases. Therefore, the development and application of positron emission tomography (PET) imaging radiotracers that selectively bind to aggregated tau in fibril form is of importance in furthering the understanding of these disorders. While radiotracers used in human PET studies offer invaluable insight, radiotracers that are also capable of visualizing tau fibrils in animal models are important tools for translational research into these diseases. Herein, we report the synthesis and characterization of a novel library of compounds based on the phenyl/pyridinylbutadienylbenzothiazoles/benzothiazolium (PBB3) backbone developed for this application. From this library, we selected the compound LM229, which binds to recombinant tau fibrils with high affinity (Kd = 3.6 nM) and detects with high specificity (a) pathological 4R tau aggregates in living cultured neurons and mouse brain sections from transgenic human P301S tau mice, (b) truncated human 151-351 3R (SHR24) and 4R (SHR72) tau aggregates in transgenic rat brain sections, and (c) tau neurofibrillary tangles in brain sections from Alzheimer's disease (3R/4R tau) and progressive supranuclear palsy (4R tau). With LM229 also shown to cross the blood-brain barrier in vivo and its effective radiolabeling with the radioisotope carbon-11, we have established a novel platform for PET translational studies using rodent transgenic tau models.

Probing the Evolution of Palladium Species in Pd@MOF Catalysts during the Heck Coupling Reaction: An Operando X-ray Absorption Spectroscopy Study

The mechanism of the Heck C-C coupling reaction catalyzed by Pd@MOFs has been investigated using operando X-ray absorption spectroscopy (XAS) and powder X-ray diffraction (PXRD) combined with transmission electron microscopy (TEM) analysis and nuclear magnetic resonance (1H NMR) kinetic studies. A custom-made reaction cell was used, allowing operando PXRD and XAS data collection using high-energy synchrotron radiation. By analyzing the XAS data in combination with ex situ studies, the evolution of the palladium species is followed from the as-synthesized to its deactivated form. An adaptive reaction mechanism is proposed. Mononuclear Pd(II) complexes are found to be the dominant active species at the beginning of the reaction, which then gradually transform into Pd nanoclusters with 13-20 Pd atoms on average in later catalytic turnovers. Consumption of available reagent and substrate leads to coordination of Cl- ions to their surfaces, which causes the poisoning of the active sites. By understanding the deactivation process, it was possible to tune the reaction conditions and prolong the lifetime of the catalyst.

A kind of carboxylic acid with malonic acid method of esterification reaction of dimethyl ester (by machine translation)

The invention belongs to the field of chemical synthesis and particularly relates to a carboxyl acid compound methyl etherification method. The carboxyl acid compound methyl etherification method comprises the following steps: in a polar solvent, using a carboxyl acid compound and dimethyl malonate as reactants, under the catalysis of a catalyst, and preparing an acid methyl ester compound through the methyl etherification reaction of the carboxyl acid. The method has the advantages of cheap raw materials, easiness in raw material acquisition, low toxicity, high safety, simple neutral salt catalyst and low dosage and is suitable for industrial application.

Flexible, dicationic imidazolium salts for in situ application in palladium-catalysed Mizoroki–Heck coupling of acrylates under aerobic conditions

The synthesis, characterization and in situ catalytic performance of new unsymmetric N,N′-disubstituted imidazolium-based dicationic salts in Mizoroki–Heck coupling of acrylates with aryl bromides under aerobic conditions are described. A series of flexible dicationic salts with varying steric and electronic properties were synthesized in good to excellent yields. All the salts were well characterized using spectroscopic techniques. X-ray diffraction analysis of two salts with the same dicationic backbone and different counter anions shows that the ligand adopts two different conformations which are influenced by the nature of the anion. Thus, the ligand is capable of changing its conformation according to the change in environment due to its flexible nature. All the synthesized imidazolium salts were found to be active in in situ palladium-catalysed Mizoroki–Heck coupling under aerobic conditions. Amongst the salts, the hydroxyl-functionalized imidazolium salt, incorporating the features of both bidentate chelating O,O ligand and carbene, shows the maximum catalytic activity. A variety of aryl and heteroaryl methyl and ethyl cinnamates were synthesized using these imidazolium salts as preligands. In addition, NMR studies confirm in situ generation of normal N-heterocyclic carbenes from the C-2 position of imidazol-2-ylidene ring. The mercury poisoning test was also performed to ascertain the nature of catalytically active palladium species. Aerobic conditions, low catalytic loading (0.5?mol%), shorter reaction times, broad functional group tolerance and good to excellent isolated yields are some of the significant features of the novel catalytic systems described here. Copyright

Chiral magnesium(II) binaphtholates as cooperative bronsted/lewis acid-base catalysts for the highly enantioselective addition of phosphorus nucleophiles to α,β-unsaturated esters and ketones

A little cooperation goes a long way: The cooperative Bronsted/Lewis acid-base supramolecular catalysts formed in situ from simple chiral magnesium(II) binaphtholate aqua complexes promoted the highly enantioselective 1,4-hydrophosphinylation of α,β-unsaturated esters with diaryl phosphine oxides and 1,2-hydrophosphonylation of α,β-unsaturated ketones with dialkyl phosphites (see scheme). Copyright

Highly effective recyclable palladium-catalyzed ligand-free heck reactions under aerobic conditions

An effective protocol was developed for the Heck coupling reactions between various aryl halides and olefins. In the presence of 2 mol% of Pd(OAc) 2, the desired products could be obtained in good yields under ligand-free and aerobic conditions. The catalytic system could be easily recycled for five times with high efficiency. Georg Thieme Verlag Stuttgart. New York.

Water is an efficient medium for Wittig reactions employing stabilized ylides and aldehydes

Water is demonstrated to be an excellent medium for the Wittig reaction employing stabilized ylides and aldehydes. Although the solubility in water appears to be an unimportant characteristic in achieving good chemical yields and E/Z-ratios, the rate of W

An efficient combination of microwave dielectric heating and the use of solid-supported triphenylphosphine for Wittig reactions

Figure presented Reaction condition: 150°C, 5 min. Olefins could be formed in an efficient way by the use of stable ylides in just a few minutes using microwave dielectric heating. The drawback with the Wittig reaction in solution phase is the formation of 1 equiv of triphenylphosphine oxide. To avoid this, the corresponding protocol using the efficient combination of solid-supported triphenylphosphine and microwave dielectric heating was developed. An even more efficient one-pot three-step Wittig reaction was also developed.