A metal-free, intermolecular syn-addition of hexamethyldisilane across simple alkenes is reported. The catalytic cycle is initiated and propagated by the transfer of a methyl group from the disilane to a silylium-ion-like intermediate, corresponding to the (re)generation of the silylium-ion catalyst. The key feature of the reaction sequence is the cleavage of the Si-Si bond in a 1,3-silyl shift from silicon to carbon. A central intermediate of the catalysis was structurally characterized by X-ray diffraction, and the computed reaction mechanism is fully consistent with the experimental findings.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6900109 | PMC |
http://dx.doi.org/10.1002/anie.201911282 | DOI Listing |
Chemistry
January 2025
Shanghai Institute of Organic Chemistry, State Key Laboratory of Organometallic Chemistry, 354 Fenglin Lu,, 200032, Shanghai, CHINA.
The unprecedent gold-catalyzed intermolecular 1,2-difunctionalization of nitriles with aryl iodides via Au(I)/Au(III) redox catalysis has been developed, providing an expedient route to the synthesis of benzoxazoles and benzimidazoles with broad substrate scope and high functional compatibility. Mechanistic investigation reveals that the Au(III)-Ar species generated via oxidative addition of o-iodophenol to MeDalphosAu+, serves as a key intermediate. Particularly and this annulation is initiated by oxidative addition, rather than the nucleophilic attack of the phenol moiety in o-iodophenol towards the nitrile.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland.
Herein, we present an efficient and practical method for multicomponent carbo-heterofunctionalization of alkenes radical-polar crossover photoredox catalysis. Employing geminal bromonitroalkanes as redox-active reagents with a wide range of O-centered nucleophiles allows rapid access to various 1,3-difunctionalized nitro compounds, including β-nitro ketones, 1,3-nitro alcohols, 1,3-nitro ethers as well as cyclic molecules.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Laboratory of Catalysis and Organic Synthesis, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland.
The azidofunctionalization of alkenes under mild conditions using commercially available starting materials and easily accessible reagents is reported based on a radical-polar crossover strategy. A broad range of alkenes, including vinyl arenes, enamides, enol ethers, vinyl sulfides, and dehydroamino esters, were regioselectively functionalized with an azide and nucleophiles such as azoles, carboxylic acids, alcohols, phosphoric acids, oximes, and phenols. The method led to a more efficient synthesis of 1,2-azidofunctionalized pharmaceutical intermediates when compared to previous approaches, resulting in both reduction of step count and increase in overall yield.
View Article and Find Full Text PDFJ Org Chem
January 2025
College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, Zhejiang, China.
In this work, a switchable synthesis of β-ketosulfone and α-chloroketone through a radical difunctionalization of alkenes is reported. The transformation works well under iron peroxo species/photoredox dual catalysis and an open-flask atmosphere, and the reaction is highlighted with good yields and a broad reaction scope. Mechanism studies show that the reaction is initiated by a formal [4 + 2] cyclization of the sulfonyl radical in a regioselective manner.
View Article and Find Full Text PDFOrg Lett
January 2025
Key Laboratory of Green and Precise Synthetic Chemistry and Applications, Ministry of Education, Anhui Provincial Key Laboratory of Synthetic Chemistry and Applications, Department of Chemistry, Huaibei Normal University, Huaibei, Anhui 235000, People's Republic of China.
Recent advances in dual catalysis involving biomimetic conversion strategies that utilize radical ligand transfer (RLT) often rely on large doses of precious metal additives. The role of these additives within the mechanism remains ambiguous, leading to complex reaction conditions, uncertain pathways, and increased costs. These challenges complicate the study of the reaction process and are accompanied by potential safety risks.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!