The palladium-catalyzed annulation of arynes by substituted o-halostyrenes produces substituted 9-fluorenylidenes in good yields. This methodology provides this important carbocyclic ring system in a single step, which involves the generation of two new carbon-carbon bonds, occurs under relatively mild reaction conditions, and tolerates a variety of functional groups, including cyano, ester, aldehyde, and ketone groups.
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http://dx.doi.org/10.1021/ol900554r | DOI Listing |
Org Lett
January 2025
State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China.
Here, we report on methods for late-stage peptide diversification through palladium-catalyzed site-selective C(sp)-H amination of tryptophan residues at the C4 position, utilizing tryptophan-amine cross-links. Our strategy enables practical access to C-N bonds, facilitating the construction of cyclopeptides via late-stage cyclodimerization of structurally complex peptides, which poses significant challenges for organic synthesis. The synthetic utility of this protocol is demonstrated through the synthesis of 30- to 38-membered macrocyclic peptides.
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January 2025
Sustainable Chemistry for Metals and Molecules, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium.
A pyridine-fused triazapentalene shows weak fluorescence in solution and is readily accessible via nitrene-mediated cyclization. In this study, a modified Cadogan reaction was used to synthesize . Palladium-catalyzed reactions have been used as post-functionalization methods.
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December 2024
State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
Zwitterionic π-allenyl palladium species are newly developed intermediates. A substrate-controlled step existed in the cycloaddition of zwitterionic π-allenyl palladium species with tropsulfimides or tropones. With the assistance of previously experimental studies, zwitterionic allenyl/propargyl palladium species was provenly found by HRMS.
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December 2024
Institute of Organic and Analytical Chemistry (ICOA UMR 7311), CNRS, University of Orleans, F-45067 Orléans, France.
The emergence of RNA viruses driven by global population growth and international trade highlights the urgent need for effective antiviral agents that can inhibit viral replication. Nucleoside analogs, which mimic natural nucleotides, have shown promise in targeting RNA-dependent RNA polymerases (RdRps). Starting from protected 5-iodouridine, we report the synthesis of -substituted-(1,3-diyne)-uridines nucleosides and their phosphoramidate prodrugs.
View Article and Find Full Text PDFJ Org Chem
January 2025
Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China.
Pd-catalyzed C4-selective alkynylation of indoles was established by employing glycine as a transient directing group. This reaction exhibits high regioselectivity with the tolerance of a wide scope of functional groups to afford diverse alkynylated indoles in moderate to good yields. Moreover, the readily accessible scale-up synthesis and further decorations to achieve multifunctionalized indoles demonstrate the synthetic potential of this protocol.
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