A desymmetrization protocol has been used to develop a palladium catalyzed enantioselective carbonylation process. Achiral cyclic bis-alkenyltriflates are converted to their corresponding monoester derivatives with selectivities of up to 96% ee.
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http://dx.doi.org/10.1039/b923186b | DOI Listing |
Mater Horiz
January 2025
School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University, Tianjin, 300350, China.
The semi-hydrogenation of alkynes into alkenes rather than alkanes is of great importance in the chemical industry, and palladium-based metallic catalysts are currently employed. Unfortunately, a fairly high cost and uncontrollable over-hydrogenation impeded the application of Pd-based catalysts on a large scale. Herein, a sandwich structure single atom Pd catalyst, Z@Pd@Z, was prepared impregnation exchange and epitaxial growth methods (Z stands for ZIF-8), in which Pd single atoms were stabilized by pyrrolic N in a zeolitic imidazolate framework (ZIF-8).
View Article and Find Full Text PDFOrg 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.
View Article and Find Full Text PDFSmall
January 2025
School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, 646000, China.
Covalent organic frameworks (COFs), known for their exceptional in situ encapsulation and precise release capabilities, are emerging as pioneering drug delivery systems. This study introduces a hypoxia-responsive COF designed to encapsulate the chemotherapy drug gambogic acid (GA) in situ. Bimetallic gold-palladium islands were grown on UiO-66-NH (UiO) to form UiO@Au-Pd (UAPi), which were encapsulated with GA through COF membrane formation, resulting in a core-shell structure (UAPiGC).
View Article and Find Full Text PDFMolecules
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.
View Article and Find Full Text PDFMolecules
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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