[reaction: see text] Strong Brønsted acids such as bis(trifluoromethanesulfon)imide catalyze the hetero-Michael addition of carbamates, alcohols, and thiols to alpha,beta-unsaturated ketones, alkylidene malonates, and acrylimides. Scope, reaction rates, and yields are superior to comparable Lewis acid-catalyzed processes.
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http://dx.doi.org/10.1021/ol034596h | DOI Listing |
Org Lett
August 2023
Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China.
A tandem allylic amination/oxa-Michael addition of vinyl methylene cyclic carbonates (VMCCs) has been developed to construct heterocycles by single palladium catalysis or palladium-organo relay catalysis. In this process, the bisnucleophiles first underwent regioselective allylic amination, and then the second nucleophilic group further completed the hetero-Michael addition reaction to form a series of heterocycles. Among them, the chiral 3,4-dihydro-2-benzo[][1,4]oxazines could be produced in medium to high yield with good enantioselectivity under a palladium-organo relay catalysis.
View Article and Find Full Text PDFPolymers (Basel)
October 2022
ICGM, Univ Montpellier, CNRS, ENSCM, 34090 Montpellier, France.
Pharmaceuticals (Basel)
November 2021
Instituto de Química Médica (IQM, CSIC) c/Juan de la Cierva 3, 28006 Madrid, Spain.
The nuclear export receptor exportin-1 (XPO1, CRM1) mediates the nuclear export of proteins that contain a leucine-rich nuclear export signal (NES) towards the cytoplasm. XPO1 is considered a relevant target in different human diseases, particularly in hematological malignancies, tumor resistance, inflammation, neurodegeneration and viral infections. Thus, its pharmacological inhibition is of significant therapeutic interest.
View Article and Find Full Text PDFChem Pharm Bull (Tokyo)
October 2021
Graduate School of Pharmaceutical Sciences, Kyoto University.
Novel innovative catalytic systems such as hydrogen-bond donors and thiourea hybrid catalysts have been developed for the asymmetric synthesis of biologically important pharmaceuticals and natural products. Benzothiadiazines possess a stronger hydrogen-bond donor ability compared to thioureas and exhibit remarkable catalytic performance for the activation of α,β-unsaturated amides. Hybrid thioureas (bearing an arylboronic acid and an ammonium salt) efficiently promote the hetero-Michael addition to α,β-unsaturated carboxylic acids and the O-alkylation of keto enols with 5-chlorofuran-2(5H)-one.
View Article and Find Full Text PDFYakugaku Zasshi
June 2021
School of Pharmaceutical Sciences, Mukogawa Women's University.
Several direct asymmetric Michael additions to α,β-unsaturated carboxylic acids with integrated catalysts comprising chiral bifunctional thiourea and arylboronic acid were developed. First, the asymmetric aza-Michael addition of hydroxylamine derivatives efficiently afforded a variety of optically active β-amino acid derivatives. Furthermore, upon detailed investigation of the reaction, tetrahedral borate complexes, comprising two carboxylate molecules, were found to serve as reaction intermediates.
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