Enatioselective reduction of oxime ethers promoted by chiral spiroborate esters with an O3BN framework is reported for the first time. In the presence of (R,S)-1, 11 aralkyloxime ethers are reduced by borane-THF at 0-5 degrees C to give (S)-1-aralkylamine in high yield and excellent enatiomeric excess (up to 98% ee). Influence of reaction conditions on the enantioselectivity of the reduction is investigated, and a possible mechanism of the catalytic reduction is suggested.
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http://dx.doi.org/10.1021/jo060123n | DOI Listing |
Angew Chem Int Ed Engl
January 2025
University of Toronto, Dept. of Chemistry, 80 St. George Street, M5S 3H6, Toronto, CANADA.
A copper-catalyzed enantioselective synthesis of borylated 1-pyrrolines from γ,δ-unsaturated oxime esters is reported. Twenty-four novel 1-pyrroline derivatives are reported in yields ranging from 26% to 96% and enantioselectivities from 74.5:25.
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January 2025
Graduate School of Pharmaceutical Sciences, Tokushima University, Shomachi 770-8505, Tokushima, Japan.
Diastereodivergent synthesis of octahydrophenanthridinone and octahydrophenanthridine skeletons, structural motifs often found in biologically active natural products, is described. We previously reported a total synthesis of a pancratistatin analog using novel octahydrophenanthridinone construction. In this study, we examined the generality of our method and its extension to octahydrophenanthridine formation.
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 PDFAdv Sci (Weinh)
December 2024
Soochow Institute for Energy and Materials InnovationS (SIEMIS), Soochow University, Suzhou, 215006, China.
Hydrogen peroxide (HO) is an important chemical in synthetic chemistry with huge demands. Photocatalytic synthesis of HO via oxygen reduction and water oxidation reactions (ORR and WOR) is considered as a promising and desirable solution for on-site applications. However, the efficiency of such a process is low due to the poor solubility of molecular oxygen and the rapid reverse reaction of hydroxyl radicals (OH) with hydrogen atoms (H).
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China.
Cyclohexanone oxime, a critical precursor for nylon-6 production, is traditionally synthesized via the hydroxylamine method under industrial harsh conditions. Here is present a one-step electrochemical integrated approach for the efficient production of cyclohexanone oxime under ambient conditions. This approach employed the coupling of in situ electro-synthesized HO over a cobalt (Co)-based electrocatalyst with the titanium silicate-1 (TS-1) heterogeneous catalyst to achieve the cyclohexanone ammoximation process.
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