A chemoselective hydrogenation of isoquinoline carbocycles was achieved by using the catalyst prepared from Ru(methallyl)(cod) and trans-chelate chiral ligand PhTRAP. The unique chemoselectivity achieved in this hydrogenation could be ascribed to the trans-chelation of the chiral ligand. The procedure for preparing the catalyst strongly affects the reproducibility of the carbocycle hydrogenation. Various 5-, 6-, 7-, and 8-substituted isoquinolines were selectively hydrogenated at their carbocycles to afford 5,6,7,8-tetrahydroisoquinolines as major products in high yields with moderate or good enantioselectivities. Some mechanistic studies suggested that the stereogenic center was created during the initial addition of H to the aromatic ring in the hydrogenation of 5-substituted isoquinolines. In other words, the stereochemical control was accompanied by the dearomatization.
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http://dx.doi.org/10.1021/acs.joc.8b00190 | DOI Listing |
J Phys Chem A
January 2025
Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan.
In this study, the radiative and nonradiative decay pathways from the first singlet excited states (denoted as S) of three bithiophene-fused isoquinolines were investigated by using the mixed-reference spin-flip time-dependent density functional theory approach. These isoquinolines, which are prepared via [2 + 2 + 2] cycloaddition reactions between three types of bithiophene-linked diynes and nitriles, exhibit different fluorescence quantum yields in response to the positions of their sulfur atoms. The decay processes, including the fluorescence emission and internal conversion, were considered.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
The Third Department of Breast Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, China; Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin's Clinical Research Center for Cancer, Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China. Electronic address:
In this study, the interaction of crebanine, an isoquinoline alkaloid, with immunoglobulin G (IgG) was evaluated. Subsequently, the anticancer effects of crebanine in MCF-7 breast cancer cells were assessed. The results demonstrate that static quenching plays a key role in the fluorescence quenching of the IgG by crebanine, and some embedded hydrophobic patches of the IgG are exposed upon interaction with crebanine, while the characteristic β-sheet conformation of the IgG was almost preserved.
View Article and Find Full Text PDFNefrologia (Engl Ed)
December 2024
Department of Medical Doctor Study Program, Faculty of Medicine, Hasanuddin University, Makassar City, South Sulawesi Province, Indonesia.
Background: Chronic kidney disease (CKD) is a major global health problem. Hyperphosphatemia is frequent in CKD and a reason for increased morbidity and mortality as it generates hyperparathyroidism, high fibroblast growth factor 23 (FGF23), and hypocalcemia. Available hyperphosphatemia therapies still have limitations, including risk of metal overload, cardiovascular calcification, and systemic adverse effects (AEs).
View Article and Find Full Text PDFDrug Dev Ind Pharm
January 2025
Quotient Sciences, Nottingham, UK.
Objective: This pilot study aimed to develop a liquid formulation of tenapanor and evaluate taste and palatability with different sweetener and flavor combinations.
Significance: Tenapanor is a first-in-class, minimally absorbed, small molecule inhibitor of intestinal sodium/hydrogen exchanger 3, indicated (as tablets) to treat adults with constipation-predominant irritable bowel syndrome. It is also approved as add-on therapy to reduce serum phosphorus in adults with chronic kidney disease on dialysis who are intolerant of, or unacceptably responsive to, any dose of phosphate binder therapy.
J Am Chem Soc
December 2024
State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
The homogeneous catalytic hydrogenation of benzo-fused heteroarenes generally provides partially hydrogenated products wherein the heteroaryl ring is preferentially reduced, such as quinoline hydrogenation, leading to 1,2,3,4-tetrahydroquinoline. Herein, we report a carbocycle-selective hydrogenation of fused -heteroarenes (quinoline, isoquinoline, quinoxaline, etc.) using the Ru complex of a chiral spiroketal-based diphosphine (SKP) as the catalyst, affording the corresponding 5,6,7,8-tetrahydro products in high chemoselectivities.
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