Continuing search for beneficial additive toward the Beckmann rearrangement (BR) of indanone oxime has revealed that common Lewis acid catalyst in methanesulfonyl chloride (MsCl) showed increasing efficiency in this ionic rearrangement. The new protocol with MsCl is superior to the classical phosphorus-based methods such as PPA and Eaton reagent, especially in the reaction of indanone oximes.
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http://dx.doi.org/10.1016/j.bmcl.2006.10.019 | DOI Listing |
Org Lett
December 2024
College of Chemistry, Sichuan University, Chengdu 610064, P. R. China.
Herein, an aerobic reconstruction of amines to amides via C(sp)-N bond and C(sp)-C(sp) bond cleavage is described. This method features a metal-free reaction, insensitivity to oxygen or moisture, and ambient air as the terminal oxidant. Preliminary mechanistic studies suggest that the reaction pathway of amine oxidation, followed by imine exchange and Beckmann rearrangement, is involved.
View Article and Find Full Text PDFNat Commun
October 2024
Centre for Membrane Separations, Adsorption, Catalysis and Spectroscopy (cMACS), KU Leuven, Celestijnenlaan 200F, post box 2454, 3001, Leuven, Belgium.
Polyolefins are the most widely produced type of plastics owing to their low production cost and favorable properties. Their polymer backbone consists solely of inert C-C bonds, making them resistant and durable materials. Although this is an extremely useful attribute during their use phase, it complicates chemical recycling.
View Article and Find Full Text PDFChem Asian J
January 2025
College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China.
Pure silica ITH zeolite is normally synthesized under neutral or acidic conditions in the presence of HF, but it is challenging for synthesis of this zeolite under alkaline conditions. In this work, it is successful for alkaline synthesis of pure silica ITH in the absence of HF using a designed organic template containing F species, showing that the sample obtained has high crystallinity associated with ITH structure, nanosheet morphology, and rich silanol nests. Very importantly, this ITH zeolite exhibited better performance in vapor phase Beckmann rearrangement of cyclohexanone oxime than that of Silicalite-1 zeolite, one of the best catalysts for this reaction.
View Article and Find Full Text PDFJ Am Chem Soc
October 2024
Key Laboratory of Biomass Chemical Engineering of Ministry of Education and College of Chemical and Biological Engineering & Key Laboratory of Applied Chemistry of Zhejiang Province, Zhejiang University, Hangzhou 310028, China.
Zeolites are typically synthesized in the presence of strong alkaline or fluoride species, which is not atom-economic for zeolite synthesis due to the high solubility of strong alkaline and fluoride species to silica. One of the solutions for this issue is to reduce solubility of silica in the zeolite synthesis, but it is challenging. Herein, we show that nucleation and growth of zeolites can occur under near neutral conditions, giving an atom-economical synthesis of zeolites with almost full silica utilization due to very low silica solubility.
View Article and Find Full Text PDFOrg Lett
October 2024
Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur Campus, Kalyani, Nadia, West Bengal741 246, India.
We report the asymmetric total synthesis of dixiamycin C (1) through the shrewd alliance of the naturally occurring monomer xiamycin A methyl ester (5) and its bromo derivative (31) following a late-stage Buchwald-Macmillan's C-N bond formation via a photoredox electron transfer approach with a less reactive carbazole nitrogen. The key step in the synthesis of monomer xiamycin A methyl ester (5) involves Buchwald's Pd(II)-mediated aerobic dehydrogenative C-N bond formation, Beckmann rearrangement, and -acetylation of an electron-rich aromatic ring of an abietane core.
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