The direct and highly enantioselective synthesis of tetrahydroacridines was achieved through the phosphoric acid catalyzed addition of enamides to in situ generated ortho-quinone methide imines and subsequent elimination. This novel one-step process constitutes a very efficient, elegant, and selective synthetic approach to valuable N-heterocycles with a 1,4-dihydroquinoline motif. By subsequent highly diastereoselective hydrogenation and N-deprotection the reaction products were easily converted into free hexahydroacridines with a total of three new stereogenic centers.
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http://dx.doi.org/10.1002/anie.201604201 | DOI Listing |
Org Lett
January 2025
State Key Laboratory of Antiviral Drugs, Pingyuan Laboratory, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China.
Highly asymmetric (3+3) annulation of diaziridines with oxiranes via C-N bond cleavage in diaziridine was achieved under 10 mol % of chiral copper(II) complex as the catalyst under mild reaction conditions. With Cu(OTf) as the Lewis acid and C-symmetric imidazolidine-pyrroloimidazolone pyridine as the ligand, diverse tetrahydro-[1,3,4]-oxadiazines were obtained by stereospecific C-N/C-O bond formation in moderate to good yields (up to 93% yield) and high diastereo- (>20:1 dr) and enantioselectivities (up to 92% ee). The catalytic cycle and stereochemical model were proposed by DFT calculation.
View Article and Find Full Text PDFCrit Rev Biochem Mol Biol
January 2025
Department of Chemistry, Emory University, Atlanta, GA, USA.
Mononuclear non-heme iron enzymes catalyze a wide array of important oxidative transformations. They are correspondingly diverse in both structure and mechanism. Despite significant evolutionary distance, it is becoming increasingly apparent that these enzymes nonetheless illustrate a compelling case of mechanistic convergence the formation of peroxo species bridging metal and substrate.
View Article and Find Full Text PDFAppl Environ Microbiol
January 2025
Joint Degree Program of Kasetsart University and Yamaguchi University, Graduate School of Science and Technology for Innovation, Yamaguchi University, Yamaguchi, Japan.
Unlabelled: Incomplete oxidation of glucose by sp. strain CHM43 produces gluconic acid and then 2- or 5-ketogluconic acid. Although 2-keto-D-gluconate (2KG) is a valuable compound, it is sometimes consumed by itself via an unknown metabolic pathway.
View Article and Find Full Text PDFJ Org Chem
January 2025
Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695019, India.
We have developed efficacious routes toward the selective synthesis of two classes of compounds such as C-3 amino-methylated indoles and 4-indol-3-yl-methylanilines from the same precursors, namely, indoles and 1,3,5-triazinanes. It is reported that the controlled cleavage of 1,3,5-triazinanes can be effected by heat for the generation of aryl imine motifs, and we observed that the presence of Lewis acid influences the course of these transformations toward different products. The reaction toward indol-3-yl-methylanilines proceeds via a nucleophilic attack of indole to the aryl imine generated from the 1,3,5-triazinanes to form an amino-methylated product which undergoes a Lewis acid mediated Hofmann-Martius-type rearrangement.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
The heterotrimeric RNA-dependent RNA polymerase (RdRp) of influenza A virus catalyzes viral RNA transcription (vRNA→mRNA) and replication (vRNA→cRNA→vRNA) by adopting different conformations. A switch from transcription to replication occurs at a relatively late stage of infection. We recently reported that the viral NS2 protein, expressed at later stages from a spliced transcript of the NS segment messenger RNA (mRNA), inhibits transcription, promotes replication and plays a key role in the transcription-to-replication switch.
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