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.

Download full-text PDF

Source
http://dx.doi.org/10.1021/jo060123nDOI Listing

Publication Analysis

Top Keywords

reduction oxime
8
oxime ethers
8
ethers promoted
8
promoted chiral
8
chiral spiroborate
8
spiroborate esters
8
esters o3bn
8
o3bn framework
8
asymmetric reduction
4
framework enatioselective
4

Similar Publications

Enantioselective Borylcupration/Cyclization of Alkene-Tethered Oxime Esters.

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.

View Article and Find Full Text PDF

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 PDF

Photocatalyzed Azidofunctionalization of Alkenes via Radical-Polar Crossover.

Angew 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 PDF

Photocatalytic Partial Water Oxidation Promoted by a Hydrogen Acceptor-Hydroxyl Mediator Couple.

Adv 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 PDF

Ambient Synthesis of Cyclohexanone Oxime via In Situ Produced Hydrogen Peroxide over Cobalt-Based Electrocatalyst.

Adv 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.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!