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A catalytic asymmetric synthesis of 3,4-dihydrocoumarins with adjacent tertiary-quaternary stereocenters by 1,6-addition/transesterification cascade reaction of α-isocyanoacetates with ortho-hydroxyphenyl-substituted para-quinone methides (p-QMs) has been developed. Using a combination of dihydroquinidine-derived aminophosphine and silver nitrate as a binary catalytic system, moderate to good yields, excellent diastereoselectivities (>20 : 1 dr) and good to excellent enantioselectivities (up to 94% ee) were achieved for a wide range of isocyanoacetates and p-QMs.
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http://dx.doi.org/10.1039/c9ob02652e | DOI Listing |
Eur J Case Rep Intern Med
August 2025
General medicine department, Universidad de Cartagena, Cartagena, Colombia.
Background: Romosozumab is a sclerostin-inhibiting monoclonal antibody that is effective and safe for anabolic treatment in patients with osteoporosis. Its main adverse effects are local; the severity of these injection-site reactions in clinical trials was generally mild.
Case Report: We present a case of a 71-year-old Colombian woman with osteoporosis at very high risk of fractures with no relevant history of drug allergies.
Beilstein J Org Chem
August 2025
Department of Natural Sciences and Sustainable Resources, Institute of Organic Chemistry, BOKU University, 1190 Vienna, Austria.
Nonreducing disaccharides are prevalent in non-mammalian glycans and glycolipids, serving as pivotal structural components in mycobacterial glycans, microbial oligosaccharide and nucleoside antibiotics, as well as biologically active mimetics of bacterial pathogen-associated molecular patterns (PAMPs). As integral components of PAMPs, 1,1'-linked disaccharide-containing biomolecules play important roles in host-pathogen interactions, cellular signaling, and pathogenesis. Accessing complex biomolecules containing nonreducing disaccharides is often hindered by difficulties in isolating them from natural sources, which can result in impure or degraded products, particularly when sensitive functional groups are involved.
View Article and Find Full Text PDFBeilstein J Org Chem
September 2025
State Key Laboratory of Chemical Resource Engineering, Department of Organic Chemistry, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
Both chiral bisoxazolines and bisimidazolines are efficient chiral ligands in metal-catalyzed asymmetric organic transformations. Chiral cyclohexane-linked bisimidazolines were prepared from optically active cyclohexane-1,2-dicarboxylic acid and 1,2-diphenylethane-1,2-diamines via the monosulfonylation of 1,2-diphenylethane-1,2-diamines, condensation of -sulfonylated 1,2-diphenylethane-1,2-diamines and cyclohexane-1,2-dicarboxylic acid, and the final cyclization with the in situ generated Hendrickson reagent.
View Article and Find Full Text PDFBeilstein J Org Chem
August 2025
College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China.
Beyond the conventional carbon-centered chirality, catalytic asymmetric transformations of isocyanides have recently emerged as a powerful strategy for the efficient synthesis of structurally diverse scaffolds featuring axial, planar, helical, and inherent chirality. Herein, we summarize the exciting achievements in this rapidly evolving field. These elegant examples have been organized and presented based on the reaction type as well as the resulting chirality form.
View Article and Find Full Text PDFOrg Biomol Chem
September 2025
Department of Chemistry & Biochemistry, North Dakota State University, Fargo-58102, USA.
The Mukaiyama-Michael (M-M) reaction is a powerful approach for carbon-carbon bond formation and can provide access to all-carbon quaternary centers and vicinal stereocenters. The use of chiral catalysts for this transformation has enabled the development of efficient asymmetric methods in which the reaction proceeds with high enantioselectivity in the presence of only a substoichiometric amount of the chiral promoter. Both chiral Lewis acid catalysts and organocatalysts have been employed.
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