A concise synthesis of the tricyclic skeleton of crotobarin and crotogoudin via a gold-catalyzed 1,6-enyne cycloisomerization reaction is reported.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/c3cc48897g | DOI Listing |
J Am Chem Soc
January 2025
Laboratory of Synthesis and Natural Products (LSPN), Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH 5304, CH-1015 Lausanne, Switzerland.
In the dyotropic rearrangement of molecules with semiflexible structures, characterized by a freely rotating static C-C bond, the formation of a mixture of products is common due to the coexistence of several energetically comparable conformers. Herein, we report that it is possible to modulate the shifting groups by adjusting the metal's coordination sphere in Pd-based dyotropic rearrangement. In the presence of a catalytic amount of Pd(II) salt, the reaction of γ-hydroxyalkenes or γ,δ-dihydroxyalkenes with Selectfluor affords fluorinated tetrahydropyranols or 6,8-dioxabicyclo[3.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
A concise and convergent synthesis of the isosteroidal alkaloids veratramine and 20--veratramine has been accomplished. A Horner-Wadsworth-Emmons olefination joins two chiral building blocks of approximately equal complexity and a transition-metal catalyzed intramolecular Diels-Alder cycloaddition-aromatization cascade constructs the tetrasubstituted arene. Other key steps include a highly diastereoselective crotylation of an -sulfonyl iminium ion and an Eschenmoser fragmentation.
View Article and Find Full Text PDFOrg Lett
January 2025
Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
Dehydrophenylalanine has a characteristic unsaturated double bond that makes it indispensable in the context of peptides and proteins. In this study, we report the Pd-catalyzed C(sp)-H arylation of dehydroalanine-containing peptides with arylthianthrenium salts under mild and base free conditions, which provides efficient access to dehydrophenylalanine-containing peptides. This approach enables the efficient coupling of different drug scaffolds and bioactive molecules to the peptides.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
Nanobiophotonics Department, Leibniz Institute of Photonic Technology (Leibniz-IPHT), Albert-Einstein-Strasse 9, 07745, Jena, Germany. Electronic address:
In recent years, nanozyme-based analytics have become popular. Among these, laccase nanozyme-based colorimetric sensors have emerged as simple and rapid colorimetric detection methods for various analytes, effectively addressing natural enzymes' stability and high-cost limitations. Laccase nanozymes are nanomaterials that exhibit inherent laccase enzyme-like activity.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Organic Chemistry, Indian Institute of Science, Bangalore 560012, India.
Despite tremendous progress of dienamine catalysis along with its application in enantioselective synthesis over nearly two decades, certain limitations, especially with respect to the regioselectivity in the dienamine generation step, continue to persist. To overcome these shortcomings of classical dienamine catalysis, we now introduce the concept of alkoxy-directed dienamine catalysis and apply it to the enantioselective arene construction by desymmetrizing -enediones through [4 + 2]-cycloaddition. Catalyzed by a diphenylprolinol silyl ether, this reaction utilizes γ-alkoxy α,β-unsaturated aldehydes as the substrate and proceeds in a highly regioselective fashion through the intermediacy of δ-alkoxy dienamine.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!