We report a novel rhodium-catalyzed rearrangement involving N-substituted 2-thiopyridones and diazoesters. This reaction proceeds through the rhodium-catalyzed formation of sulfur ylides, followed by a direct C-N bond cleavage to achieve N-to-C 1,4-pyridyl migration. The protocol can be used to construct various thiopyridines possessing tetrasubstituted carbon stereocenters in moderate to excellent yields, which expands the transformation pattern of sulfur ylide intermediates in rearrangement reactions.
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http://dx.doi.org/10.1021/acs.orglett.3c00068 | DOI Listing |
Chemistry
December 2024
Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai, 980-8578, Japan.
Reactions of cyclic thioureas (1,3,4,5-tetramethylimidazol-2-thione and 1,3-dimethylimidazolidin-2-thione) and ureas (1,3,4,5-tetramethylimidazol-2-one and 1,3-dimethylimidazolidin-2-one) with an isolable dialkylsilylene were examined. In these reactions, cyclic thioureas served as sulfur and NHC (N-heterocyclic carbene) sources, and the corresponding silanethione and NHC-derived products formed via silanethione-NHC complexes. Reactions of cyclic ureas with the silylene afforded a new NHC and an isolable azomethine ylide.
View Article and Find Full Text PDFBeilstein J Org Chem
December 2024
Department of Chemistry, University of Waterloo, 200 University Ave W., Waterloo, Ontario, Canada.
A novel study on the hypervalent iodine-mediated polyfluoroalkylation of sulfoxonium ylides was developed. Sulfoxonium ylides, known for their versatility and stability, are promising substrates for numerous transformations in synthetic chemistry. This report demonstrates the successful derivatization of sulfoxonium ylides with trifluoroethyl or tetrafluoropropyl groups, and provides valuable insights into the scope and limitations of this approach.
View Article and Find Full Text PDFOrg Lett
December 2024
Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, 688 Yingbin Road, Jinhua 321004, China.
An unexpected cascade reaction of enyne-amides with sulfur-ylides has been developed. This cascade reaction involves cycloisomerization, dearomatic cyclopropanation, ring-opening rearomatization, and subsequent cyclopropanation, differing from the common [2 + n] cyclization of enyne-amides. A variety of (spirocyclopropane)dihydrofuran derivatives have been efficiently and conveniently synthesized in a single vessel, exhibiting excellent diastereoselectivity and good functional group tolerance.
View Article and Find Full Text PDFJ Org Chem
December 2024
College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, PR China.
A novel annulation reaction of amidines with sulfur ylides and nitrobenzenes has been developed, affording various novel 4-hydroxy-5-phenylaminoimidazoles in moderate to excellent yields. The 4-hydroxy-5-phenylaminoimidazoles have been further converted into α-ketoamide and imidazol-4-imine derivatives. Moreover, a plausible mechanism for this multicomponent reaction is proposed.
View Article and Find Full Text PDFOrg Lett
December 2024
Université de Haute-Alsace, Université de Strasbourg, CNRS, LIMA, UMR 7042, 68000 Mulhouse, France.
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