3665-51-8Relevant academic research and scientific papers
Vilsmeier-Haack reagent: An efficient reagent for the transformation of substituted 1,3-naphthoxazines into xanthene-type dyes
Farat, Oleg K.,Ananyev, Ivan V.,Varenichenko, Svetlana A.,Tatarets, Anatoliy L.,Markov, Victor I.
, p. 2832 - 2842 (2019)
Derivatives of 1,3-naphthoxazines containing from five to seven-membered spiro ring – under Vilsmeier–Haack reaction conditions are rearranged into novel xanthene-type compounds. All synthesized aminochromene derivatives fluoresce in organic solvents with extra large Stokes shifts (100–133 nm). It was found that compounds containing five-membered annulated aliphatic rings in methanol solution have the best spectral characteristics. These compounds have moderate quantum yields of 28.36–28.94%, and extra large Stokes shifts 106 and 115 nm.
Bi-aryl analogues of salicylic acids: Design, synthesis and sar study to ameliorate endoplasmic reticulum stress
Kim, Ye Eun,Kim, Dong Hwan,Choi, Ami,Jang, Seoul,Jeong, Kwiwan,Kim, Young-Mi,Nam, Tae-Gyu
, p. 3593 - 3604 (2021/08/30)
Introduction: Endoplasmic reticulum (ER) stress condition is characterized as the accu-mulation of misfolded or unfolded proteins in lumen of ER. This condition has been implicated in various diseases and pathologies including β-cell apoptosis, Alzheimer’s disease and atherosclerosis. We have reported that hydroxynaphthoic acids (HNA), naphtha-lene analogues of salicylic acid (SA), reduced ER stress. In this study, we explored structural modification to bi-aryl analogues of SA. Methods: Palladium-catalyzed cross-coupling was applied to synthesize bi-aryl analogues of SA. Anti-ER stress activity was monitored by using our cell-based assay system where ER stress is induced by tunicamycin. To monitor ER stress markers, ER stress was induced physiologically relevant palmitate system. Results: Many analogues decreased ER stress signal induced by tunicamycin. Compounds creating dihedral angle between Ar group and SA moiety generally increased the activity but gave some cytotoxicity to indicate the crucial role of flat conformation of aromatic region. The best compound (16e) showed up to almost 6-fold and 90-fold better activity than 3-HNA and tauro-ursodeoxycholic acid, positive controls, respectively. ER stress markers such as p-PERK and p-JNK were accordingly decreased in Western blotting upon treatment of 16e under palmitate-induced condition. Conclusion: Anti-ER stress activity and toxicity profile of bi-aryl analogues of SA could provide a novel platform for potential therapy for protein misfolding diseases.
Synthetic modeling of the structure and function of the rare-earth dependent methanol dehydrogenase cofactor
Knasin, Alison L.,Schelter, Eric J.
, p. 19 - 55 (2021/04/19)
Historically, rare-earth ions have been considered irrelevant to biology. Recently, the active sites of certain methanol dehydrogenase (MDH) enzymes have been shown to contain a redox-inactive, rare-earth (RE) cation coordinated by the redox-active pyrroloquinoline quinone (PQQ) cofactor. Importantly, it was demonstrated that rare earths were essential for the growth of certain methylotrophs that incorporated the XoxF-MDH. In this chapter, we summarize the optimized synthesis of a previously published rare-earth complex that serves as a model of the active site of this RE-containing MDH enzyme. The structure and reactivity of the metalated complex, [La(LQQ)(NO3)3] are also discussed. [La(LQQ)(NO3)3] catalytically oxidizes the test alcohol substrate, p-methylbenzyl alcohol, 4MeBnOH, to p-methylbenzaldehyde, 4MePhCHO, in the presence of a base (2,6-lutidine) and a terminal oxidant (ferrocenium hexafluorophosphate) with ~ 17 turnovers. By studying this synthetic model, we have developed a body of evidence about both the reactivity and the mechanism of dehydrogenation of alcohols as a molecular analogue to a native, rare-earth dependent enzyme.
Asymmetric Hydrogenation of Cationic Intermediates for the Synthesis of Chiral N,O-Acetals
Sun, Yongjie,Zhao, Qingyang,Wang, Heng,Yang, Tilong,Wen, Jialin,Zhang, Xumu
supporting information, p. 11470 - 11477 (2020/08/10)
For over half a century, transition-metal-catalyzed homogeneous hydrogenation has been mainly focused on neutral and readily prepared unsaturated substrates. Although the addition of molecular hydrogen to C=C, C=N, and C=O bonds represents a well-studied paradigm, the asymmetric hydrogenation of cationic species remains an underdeveloped area. In this study, we were seeking a breakthrough in asymmetric hydrogenation, with cationic intermediates as targets, and thereby anticipating applying this powerful tool to the construction of challenging chiral molecules. Under acidic conditions, both N- or O-acetylsalicylamides underwent cyclization to generate cationic intermediates, which were subsequently reduced by an iridium or rhodium hydride complex. The resulting N,O-acetals were synthesized with remarkably high enantioselectivity. This catalytic strategy exhibited high efficiency (turnover number of up to 4400) and high chemoselectivity. Mechanistic studies supported the hypothesis that a cationic intermediate was formed in situ and hydrogenated afterwards. A catalytic cycle has been proposed with hydride transfer from the iridium complex to the cationic sp2 carbon atom being the rate-determining step. A steric map of the catalyst has been created to illustrate the chiral environment, and a quantitative structure–selectivity relationship analysis showed how enantiomeric induction was achieved in this chemical transformation.
Method for producing naphthalene carboxylic acid amide compound
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Page/Page column 9, (2008/06/13)
The present invention provides a method for producing a naphthalenecarboxylic acid amide compound represented by formula [1] comprising, reacting a naphthalenecarboxylic acid halide compound represented by formula [2] with ammonium acetate in a solvent having an ether bond. According to the method of the present invention, a naphthalene carboxylic acid amide compound can be obtained at high yield and at low cost.
Thiazoline acid derivatives
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, (2008/06/13)
Thiazoline acids and derivatives useful as chelators of trivalent metals in therapeutic applications have been prepared.
Synthesis and biological evaluation of naphthyldesferrithiocin iron chelators
Bergeron, Raymond J.,Wiegand, Jan,Wollenweber, Markus,McManis, James S.,Algee, Samuel E.,Ratliff-Thompson, Katie
, p. 1575 - 1581 (2007/10/03)
The synthesis and iron-clearing properties of the naphthyldesferrithiocins 2-(2'-hydroxynaphth-1'-yl)-Δ2-thiazoline-(4R)-carboxylic acid, 2-(2'- hydroxynaphth-1'-yl)-Δ2-thiazoline-(4S)-carboxylic acid, 2-(3'- hydroxynaphth-2'-yl)-Δ2-thiazoline-(4R)-carboxylic acid, and 2-(3'- hydroxynaphth-2'-yl)-Δ2-thiazoline-(4S)-carboxylic acid are described. While the bile duct-cannulated rat model clearly demonstrates that the 3'- hydroxynaphth-2'-yl compounds are orally active iron-clearing agents and the corresponding 2'-hydroxynaphthyl-1'-yl compounds are not, in the primate model none of the benz-fused desazadesferrithiocin analogues are active. Oral versus subcutaneous administration of these ligands strongly suggests that metabolism is a key issue in their iron-clearing properties and that these benz-fused desferrithiocins are not good candidates for orally active iron- clearing drugs.
