The catalytic asymmetric epoxidation of alpha,beta-unsaturated amides using Sm-BINOL-Ph3As=O complex was succeeded. Using 5-10 mol % of the asymmetric catalyst, a variety of amides were epoxidized efficiently, yielding the corresponding alpha,beta-epoxy amides in up to 99% yield and in more than 99% ee. Moreover, the novel one-pot tandem process, one-pot tandem catalytic asymmetric epoxidation-Pd-catalyzed epoxide opening process, was developed. This method was successfully utilized for the efficient synthesis of beta-aryl alpha-hydroxy amides, including beta-aryllactyl-leucine methyl esters. Interestingly, it was found that beneficial modifications on the Pd catalyst were achieved by the constituents of the first epoxidation, producing a more suitable catalyst for the Pd-catalyzed epoxide opening reaction in terms of chemoselectivity.
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http://dx.doi.org/10.1021/ja028454e | DOI Listing |
Chem Soc Rev
January 2025
School of materials science and engineering, Smart sensing interdisciplinary science center, Nankai university, Tianjin 300350, P. R. China.
The inspirations from nature always enlighten us to develop advanced science and technology. To survive in complicated and harsh environments, plants and animals have evolved remarkable capabilities to control fluid transfer sophisticated designs such as wettability contrast, oriented micro-/nano-structures, and geometry gradients. Based on the bioinspired structures, the on-surface fluid manipulation exhibits spontaneous, continuous, smart, and integrated performances, which can promote the applications in the fields of heat transfer, microfluidics, heterogeneous catalysis, water harvesting, Although fluid manipulating interfaces (FMIs) have provided plenty of ideas to optimize the current systems, a comprehensive review of history, classification, fabrication, and integration focusing on their interfacial chemistry and asymmetric structure is highly required.
View Article and Find Full Text PDFTetrahedron Lett
October 2024
Department of Chemistry, University of California, Berkeley, CA 94720, USA.
Neutral dual hydrogen bond donors (HBDs) are effective catalysts that enhance the electrophilicity of substrates or the Lewis/Brønsted acidity of reagents through an anion-binding mechanism. Despite their success in various enantioselective organocatalytic reactions, their application to transition metal catalysis remains rare. Herein, we report the activation of gold(I) precatalysts by chiral ureas, leading to enantioselective hydroarylation of allenes with indoles.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Ivanovo, Russia.
Directed synthesis of novel water-soluble asymmetric porphyrins containing in a molecule three cationic fragments and residues of adenine (PorAD) was performed, using metal-complex catalysis method. The interaction of the synthesized porphyrin with the oligonucleotides poly[d(AT)2] and poly[d(GC)2] and double-stranded deoxyribonucleic acid of the calf thymus (ctDNA) was studied by means of spectral and hydrodynamic methods. It was established that PorAD intercalated not only into GC-enriched regions, but also into AT regions.
View Article and Find Full Text PDFAdv Mater
December 2024
School of Chemistry and Chemical Engineering and State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240, China.
Asymmetric catalysis is essential for addressing the increasing demand for enantiopure compounds. Recent advances in reticular chemistry have demonstrated that metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) possess highly regular porous architectures, exceptional tunability, and the ability to incorporate chiral functionalities through their open channels or cavities. These characteristics make them highly effective and enantioselective catalysts for a wide range of asymmetric transformations.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Tianjin University, School of Materials Science and Engineering, Bldg 31, Tianjin, CHINA.
Single-atom catalysts (SACs) with nonplanar configurations possess unique capabilities for tailoring the oxygen reduction reaction (ORR) catalytic performance compared with the ones with planar configurations, owing to the additional orbital rearrangement arising from the asymmetric coordination atoms. However, the systematic investigation of these nonplanar SACs has long been hindered by the difficulty in screening feasible nonplanar configurations and precisely controlling the coordination structures. Herein, we demonstrate a combined high-throughput screening and experimental verification of nonplanar SACs (ppy-MN3) for highly active and selective 2e- ORR electrocatalysis.
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